u/Cool-Illustrator-185

Hey everyone complete newbie here!

I've only ever owned a single betta as a kid and recently decided to come back to try my hand again ive been looking online and trying to do research but it all seems to be America focused I have 2 tanks I bought for 10 bucks im going to clean (obviously) ones 23 litres and the other is just on 70 I want to start small but have no real idea where is best to start im in a fairly cold region through winter but can hit mid 30s in summer (good old QLD) any help /advice is massively appreciated.

I would like to work towards a 20ish gallon style community tank set-up over a year or so thank you!