Pretty easy honestly. Pick the frames you like, enter in your prescription, choose lens options like transitions/anti glare then pay and you get em in a couple days to a couple weeks depending.

Just like anything else shop around - some of the "cheap" online places still charge a ridiculous amount.

Name brand doesn't mean much either - for example - generic transition lens coating works just as well as the name brand stuff for most applications for a fraction of the price.

I also got them online, Zenni, think I got away with $70 or so

I find glasses online are about half the price of a local place. $500+ locally, about $250 online for the same thing. Progressives drive most of the cost.

If you can get am exam locally for a good price, you're good to go. Just make sure they include the PD - Pupillary Distance, they sometimes don't, though it's part of your prescription and they're required to supply it.