Lower your expectations. "This has to be the trip of our lives, we worked so hard, ..." is a recipe for disaster. Things will be different from what you have planned. You will be disappointed by some things, others may just not work out at all. If you get hung up on that, you won't be able to enjoy all those little moments that make a trip memorable.

If you have to leave the beautiful little Café early because that one big thing on your checklist is closing in an hour and tomorrow you have to leave early for the next stop, you won't be left with any nice memories, only pictures of things that have already been photographed a million times.

My advice: already make plans for the next trip. Yes, you won't be making it back overseas in a while, but there is just no correllation between how far you travel, how much you spend and how good of a time you have. I've traveled a LOT all over the world and some of my best memories were made in places I could reach by car. The biggest disappointment was a long, expensive overseas trip that was "maybe the last big holiday before we get kids".

Take the pressure out, this is just a holiday of many more that will follow. Don't plan too many things in advance, don't make a list of "must sees". Make sure that if you like a place, you can just stay a few more nights.

I was recently on a three week trip through Italy, from the alps in the north all the way to Sicily in the south. We stayed for a few more nights on a nice little camp in the middle of nowhere, with no major attractions nearby, just because we enjoyed lying in a hammock and reading a book. We skipped Rome instead.

I am guessing from context you're an American going to Europe.

The US is big; distances in Europe is more manageable. However, we've packed a bunch of stuff into every square kilometre. Just because you can do Paris, Venice, Florence, Rome, and Naples all in a week doesn't mean you should. I lived a while in Florence, and I always overheard American tourists talking about how they "saw" all these great European cities in just a day before moving on. They didn't see shit other than the Eiffel tower and the Ponte Vecchio.

Find a place you want to experience, and try to actually experience it. Go to museums. Eat their food. Visit small unknown places. Walk around. Learn about the place.

Europeans don't generally love Americans. We mostly tolerate them. We kind of like their culture, but our favourite Western movies are Italian.

This is not an attack, but a fair warning. Don't parade how American you are expecting people to treat you better - the best you can hope for is that they'll expect you to leave a fat tip. Try to mimic social codes around you. Don't be the loudest person around - and if the loudest people around you are Americans, they're either being obnoxious or you're in a tourist trap.

Don't ever brag.

Investigate when you can eat and what you can eat when. Lunch and dinner times vary from country to country and sometimes city to city. If you're hungry between 14 and 18 in France or Italy you'll be lucky if you can settle with a sandwich. Restaurant closing times vary a lot too - a Pizzeria in Italy will open at 19, in Denmark it will close at 20.

When in Rome and all that. Macdonald's might do in a pinch, but Europe is a continent of cheese, wine, beer, and regional specialties. Find out what people eat in the city where you are. You probably don't want to order a paella in Andalucia; only Americans order bolognese in Naples.

Especially in France, don't expect everyone to speak English. They might not be very comfortable with it, and starting a conversation in English an awful start. Learn a few phrases. In France, always start any interaction with a bonjour or bonsoir. At the very least learn how to ask people if they speak English in their own language. In many countries their response will be "of course I do", but chances are they'll still appreciate the effort.

And good luck!! It's a wonderful continent, especially if you're interested in art, food, or history.

Edit: Also, if you're in a touristic city looking very American or talking loudly in American English, you need to keep a tighter watch on your personal belongings than anyone else around you. You're being targeted by pickpockets.

Others have said it, but I'll stress it some more. Don't overplan. Whenever I go somewhere I make a list of all the places I wanna go to and I only schedule one place/day. Two at most if they're small things. But don't plan a museum in the morning and then a second place/museum in the afternoon, for example. You'll never make it to the second place. Or you will but you'll be too tired to enjoy it.

1-2 places/day are enough. Trying to cram too much stuff into a day will ruin your trip, really.

Pro tip: trips aren't perfect. It's life, nothing will be perfect. BUT learn to roll with things and don't take it super hard of something goes awry. Some of my best memories and stories are from agonizing parts of trips.

Also, don't plan out all you time there, leave some free time open to list about. You'll be there with your SO, you intend to spend quality time with them, it's great to have open time to go do something that catches either of your attentions rather than dismiss it due to "vacation appointments" like a tourist spot you planned.

Take pictures or memorabilia of whatever suits you, I have pictures of cool mirrors in hotels, or a wonky bathtub. Again don't dwell too much on making it perfect, the perfect spot, the perfect picture etc. I have a hilarious picture of an SO with a guy running across the shot, I got him in multiple frames. Still some of my favorites from the trip.

Grab some local currency before you arrive so it's on hand, know what ATMs can allow you to pull money from for free (Bank of america has a bunch of partners all over Europe) and Don't let the TSA disappear it from your bag.

Where you going? Where you coming from?

For general non-specific advice, be flexible, have a plan, have a backup plan have a backup backup plan. It's inevitable something's going to go wrong, don't let that bring your mood down, treat every event as its own adventure. Meet changes with joy, and you'll have more fun overall.

Do fewer things better. Don’t try to cram a million things into a day. Set a “if we do X and Y today then we will be satisfied “ goal to keep perspective. It is easy to get overwhelmed by all the things you could do, so try and be satisfied with what you did do.

Others have already said to let go about everything being perfect, because there will be things outside of your control that you cannot account for, so I won’t harp on about that.

Instead, I recommend a little pre-trip prep at home to make the end of your trip a dream as well. Take some time to clean the house/apartment, do the dishes and laundry, make the bed.

There is nothing like coming home after a long trip, but coming home to a mess or chores after a (hopefully) amazing time is a terrible way to cap off your vacation, so do yourselves a favor and spend a couple hours on making home perfect before you leave.

If you are going to a non-english speaking country, do not expect anybody to speak english. Learn some basic phrases on the local language.

If you need any medical assistance, do not hessitate and go to a hospital. Even better if you have some travel insurance.

Do not propose. Thank me later.

• Buy good walking shoes, not just basic sneakers. That pair of chucks or vans may look cool, but they are terrible for standing and walking for long periods. Your feet will thank you later.

• Download offline maps so you can find your way if you lose data/reception.

• If your travel is focused on going around and not staying put at your accommodation (i.e. resort), don't bother with getting super expensive hotels. What's important is that it's clean and safe. You can use the money saved for when you're actually going around.

• Save scans of your passports and other important documents on your phone or somewhere online, in case it gets lost or stolen.

• Bring a pen. You’ll need to fill out forms as you enter and exit ports. It’s a hassle having to borrow a pen from other travelers.

• Bring a small pouch bag for you phone, wallet, keys, and passport. That way you can securely carry it with you wherever you go without dragging around your luggage. Edit: Here's a prime example of why a small bag you can wear on your body is helpful. Happened just a few days ago: https://youtu.be/xEUtmS61Obw

Be more concerned about enjoying your girlfriend than enjoying the place.

This probably isn't helpful, but I like guided tours where a tour guide tells you about the castles and churches while everyone dutifully takes pictures to prove they were there. The guide/agency arranges the busses/boats and hotels so all you have to do is follow along with the program. The downside is that it always costs too much. The upside is that you spend less time waiting in lines because the planners will have all that worked out with the various sites. Some of those trips are almost exclusively senior citizens, but some have wider age ranges. Either way, you get to meet a set of fellow travelers who may become permanent online friends.

Honestly, expect shit to go wrong. Sounds like you’ve gotten all the important shit done. You’ve got a plan, you’ve been working towards it for a while and seems like your partner is into it as well.

We had a similar trip a few years back, first time overseas for some of us. Lots of planning and preparation went into it. Then our trip planner fucked up one of our bookings in Paris. Meaning we almost missed out on doing some tour that ended on the Eiffel Tower. A couple of times trains were missed/delayed.

The only times the trip strayed away from being the fantastic trip it was is because people let small (and sometime not so small, to be fair) disappointments or missed expectations turn into high stress/anxiety events. You’re going overseas, shit may go wrong; be ready for it and be cool with it (while also making sure you have travel insurance). Also take time away to do shit yourselves that the other may not want to do and always have set meeting times and locations to check in if you do.

I think my wife and I have this down pretty well, so here’s our guidelines:

1. Figure out some structure. We usually plan one “thing” per day. Whether that’s catching a train between cities, a particular museum, or a guided tour. This helps with pacing when you are there because you don’t have to think too much day to day, but you won’t feel like you wasted a whole day.
2. Figure out food options. I usually make a Google Maps saved list of dozens of different kinds of restaurants in every city. The goal here isn’t a plan, but simply to have good options no matter where in the city you end up. You will have less than one dinner per day of travel after you consider traveling days, so don’t waste it on some tourist trap that you happen to be nearby when the time comes. I’ll usually make a dinner reservation for every other night to make sure we get some incredible meals.
3. Naps. It’s vacation, just plan on taking a nap everyday. Our first trip was together was to southern Spain and we’ve just decided that siestas are for us. This also helps with jet lag, staying up late to do local stuff, and having something that you won’t feel bad about canceling if something comes up.
4. Self-Guided tours on the first day. If you are Americans traveling to Europe, I’d recommend the Rick Steve’s app and then splitting a pair of AirPods together as you walk around. He does the whole look here, walk here, turn left tour thing, but it’s self paced. We try to do this the first day we’re in a city so we get an idea what the major areas are. Self paced is nice because he’ll say something like “this is a great coffee shop” and we can just pause it and grab coffee if we want. Split the AirPods so you can really hear your surroundings and the tour is something you share.
5. Any plans you make are just so you know your options. If you plan on taking a train between cities, look at when the next train is in case you have to miss it. Same with dinner reservations or museums. If it doesn’t feel fun or convenient, you’ll want to know what your alternatives are so it’s never “something or we read in the hotel all day”. Think about “it’s raining, so we’ll go to a museum instead”. Rick Steve also does museum tours.

you're leaving out a lot of relevant info-- where are you going? do they speak english, or do one of you speak the destination's language? will you have a guide? do you have your international cell phone plan squared away?

as others have said, if you think or expect everything to be perfect, you're in for a disappointing trip. it won't be "perfect" because nothing ever is. relax and try to enjoy it for the experience

Call your bank and credit cards you have and let them know you will be leaving the country. This will hopefully stop them from putting holds on your account that prevents you from spending.

Have fun, and when you get tired, chill out and relax.

Don't make yourself "have fun" if you feel more like relaxing

Figure out how many drinks you can have without getting drunk, and then drink only half that many. Altitude effects how hard alcohol hits you. Also, don't mix alcohol and sleeping or anxiety medications.

Plan some alone time. You don't need to be together the entire time and it is ok to plan to do different things.

Don't try to make this trip perfect. Mistakes and bad things will happen on the trip; this is fine. It is better to focus on the good. If anything bad happens, it makes for a good story.

Don't talk to random people coming up to you on the street, especially if they are speaking in your language.

Take something to help with the jet lag.

Get in decent walking shape. If you or your girlfriend have a sedentary life, it is going to be a big change when you are walking around everywhere. If you don't do 10,000 steps a day on average now, start walking more while you have time to train.

Do you both already have passports? Visas? Travel insurance?

How are you getting there and back? How are you getting around in-country?

How will you spend money in that country? Is it one that requires cash? How do you get that cash if so?

Can you speak the language? You may want a phrasebook.

How will your phone work or will you turn it off completely to avoid roaming charges?

Will you be doing laundry? Do you know how to buy detergent and such?

Edit: also, how will you charge things? Are outlets and voltage the same? Do you need an adapter (fine if voltage same) or converter (such as when you're form a ~100v country going to a ~200v country that would fry your electronics with just an adapter).

Create a checklist of things to pack, bring or prepare. Helps to know you definitely packed 3 sets of clothes and have your passport ready.

Keep all your paperwork in a file easily accessible. Try to print stuff if you can because that doesn't run out of battery.

If you're the type to fret over prices, have a currency exchange rate ready so you know how much things will cost in your currency. Just a good mental shorthand reference. Have it be what you exchanged it for at the time not whatever the current rate is.

Look up how social norms in that country differ from your own. It would suck to need the bathroom and to then find out, while in the bathroom stall, that toilet paper is not provided because the norm is that everyone brings their own, and to hope that 1) there's someone in the stall next to you 2) who understands you and 3) is nice enough and 4) has enough to share with you.