There's a lot of bro-science in here ("Your body metabolizes sugar to basically fat", no, it doesn't, sugar is just a simple, easily metabolized carbohydrate, and as long as you aren't exceeding your caloric intake regularly, it's fine).

You can loose weight by exercise alone, but it's a challenge; most people tend to start eating more (consciously or not) once they're exercising. Exercise is only have of the equation. Diet is the other part. Most people are very, very resistant to changing their diet, because they have an emotional connection with food. Think about that; is what you eat more important to you than how you feel? Are you willing to make life-long changes, or are you just trying to have a beach body? "Dieting" is setting yourself up for failure; you want to be changing your entire lifestyle and relationship with food and movement.

So, let's start off with something super-important: talk to a registered dietician. Don't make radical changes to your diet without consulting a professional that's qualified to give answers to YOU.

Second: spot fat reduction is not a thing, unless you want to go the surgical route. You need to reduce body fat all over in order to reduce fat on your neck and waist.

Third: do a resting metabolic rate test, and find out how many calories you burn just existing. That gives you an idea of what you need to eat to maintain your weight, what you need to your macros (daily carbohydrate, protein, and fat intake), and where you need to be as far as exercising. At one time you could get them done at certain Lifetime Fitness locations, and they were a couple hundred bucks. Without knowing this, dieting and exercise is being done blindly.

Fourth: Once you know your metabolic rate, and you've consulted with a dietician, start keeping track of everything that goes in your mouth in a day. Start by just taking a photo, and get used to that. (And yes, everything; every drink that isn't plain water, every single thing you swallow.) Once you've gotten used to that, then start writing it down. Once you can reliably write everything down, start measuring everything. How many ounces of Cheerios go in your bowl in the morning, how much milk, and how many eggs are you scrambling? Once you've got that? then start comparing that to your macros. How many grams of carbs, protein, and fats are in your Cheerios, milk, and scrambled eggs (and don't forget to count the butter that goes in the pan before you scramble your eggs!)? That tells you where you are, and where you need to add, and where you need to cut.

While you're doing that:

Start with cardio, just to get in the habit of moving. I would suggest buying a heart rate monitor (I have a Garmin Instinct). Figure out your maximum heart rate (220 minus your age), and generally work at 60-80% of that, for 30-60 minutes at a time. Working above 80% increases your aerobic threshold, staying below 50% isn't going to give you a significant benefit.

Weight training should be your bread and butter. Cardio burns calories now, weight training burns calories for up to 3-4 hours after you're done in the gym, and muscle burns more calories just existing than fat does. If you have never done weight training before, I would strongly suggest that you hire a personal trainer. Look for a trainer that has at least a BS in exercise science or kinesiology, and a training certification from ASCM (American College of Sport Medicine) or the NSCA (National Strength and Conditioning Assoc.). Other physical trainer certifications are worth about as much as the paper they're printed on, and I say this as someone that was certified through NASM. ASCM and NSCA have a very strong science-based approach that other certifying bodies lack. DO NOT sign up for months and months of training, unless you simply can't motivate yourself, or are unable to replicate training prompts on your own; you want someone that will create a program for you to follow for several months that isn't just trendy, bullshit exercises (see also: fitness "influencers"), and coach you through the proper way to complete the motion so that you can do it safely and effectively. Unless you have significant movement deficiencies, your goal should be to use freeweights and for almost everything. A trainer should be able to tailor your programming to your goals; there's no one-size-fits-all. Generally speaking, if you've never lifted weights before, 30 minutes of fairly intense work is about all you'll be able to manage.

Finally: Best case, with perfect diet and exercise, you should be losing no more than 1-2 pounds of fat per week. That's the most that will be sustainable. Don't worry about raw weight; worry about measurements, and body composition.

Is this a lot? Yeah, it is. And it's barely scratching the surface.

But everyone starts on the ground floor.