Feels like I'm new to pools!

Hello all!
Where to start, used to maintain a pool at a health spa 20 years ago. Now I've got the AG setup in the backyard and hope that remembering how to take care of it is like riding a bike.

Decided on on an 18x48 Coleman AG. This way I can teach my toddler (with autism) how to swim in a safe quiet area. Plus the pool will help the wife get used to the humidity here.