Have you tried shopping online? I live in a small town, so much of my shopping happens online at amazon. It's cheaper for me that way too and I don't have to worry about fighting traffic.
Pics can be tricky at the beginning. I found it's easier to turn on a ceiling light (for extra light) and take dozens. Odds are they'll be still for one of them! XD
5gal is a good size. You won't have to worry too much about PWC, there's plenty of room for décor and even plants, you can cycle it, and there are a few tank mates that can Btw added (depending on hardness) like a snail or shrimp. Shrimp are great cleaners, but they need plenty of hiding places because some bettas see them as snacks!