Here’s a few things you should answer for yourself before you start looking:
What kind of tires do you want? Skinny street, wide street, off-road, fat ones, etc.
Do you want it to fold in half for better storage in an apartment, at work, or in your small car?
Do you want good full coverage fenders that are close to the wheels for riding in the rain without it ending up all over your back and legs?
How far do you want to be able to travel round trip?
Are there any other important features you want?
What’s your price range? (I know you already said not too expensive.)
I personally bought a folding bike from https://www.greenbikeusa.com/ because they are cheap, they can fold, they have full coverage fenders, they come with a rack, and I was able to attach a basket. it’s a cheap Chinese bike that arrives folded up in a box partially disassembled and the shifter needed calibrating so as long as you are OK with that it’s been a great value.