@
arimnestos, most of us are not deliberately being unhelpful, but we really don't have enough information to make helpful comments. @
Kedosto's fit recommendation is spot on, as is @
dedhed's coop recommendation. Since it appears you don't know what size bike you need, I'd go with finding a coop and look for a bike there. Tuesday-Thursday mornings seem to be the dead time at most bike shops, so if you can go then, they'll have time to talk with you, size you up, and get you a bike that'll work for you.
Alternatively, perhaps one of your friends rides bikes enough to be a resource. If you can talk to him/her to narrow down sizes, take him with you to look at the bikes that might fit. He can help you assess the bike -- frame, wheels, tires -- and figure out if it's rideable, or what it would take to make it rideable. If you find a $250 bike that's been sitting in a garage for 30 years, and need to take it to a shop to replace cables, brake pads, open up all the bearings and repack them with fresh grease, then reassemble and adjust everything, and put some fresh tires on to replace the dry-rotted rubber-ish things on the wheels, you could be looking at some money. Buy a bike for $250, spend another $250 getting it ready to ride, and you still have a 30 year old bike. Maybe the $650 new bike, with a warranty, a shop that you know will work with you and explain how to shift and brake, a staff that tells you what to look out for and what kind of service or replacement parts you may need, mechanics who'll adjust your cables after a month or two -- maybe it's not that expensive after all?
Re: $20 lunches, all of those were a mistake. I only remember one, and all I could taste was the grease off the steak sandwich. If I've had more than one $20 lunch, it/they was/were mistakes too, since they were forgettable and obviously overpriced.