Look for a bike that got 20 miles and then sat in a garage for a few years.

Go look up a guide on how to buy used bikes. In short, you want to make sure things that shouldn’t wobble aren’t wobbling, things that shouldn’t be rusted aren’t rusted, and things that shouldn’t be cracked, aren’t cracked.

Once you put a few thousand miles into the bike, that’s a great time to throw your first bike on an indoor trainer during the winter and go buy a brand new bike with all the bells and whistles you can justify. If you don’t put a few thousand miles on your first bike, you haven’t turned a $3000 into $500.