New to Trailer camping, what are some must haves, and wants

You will learn quick what your next trailer needs. At minimum 15” running gear, 4500 lb axles 50-90 gallons of water. 30/30/30 tanks are refilling fresh and dumping gray if you are State Park camping at 11 am on a Saturday. Been there done it. Now I avoid Campgrounds and strictly boondock with my pup.
I bring 48 gallons of water for two people or 80 gallons if my kids come. I bring bikes, canoe, fishing gear, games, toy bin, ect. Kids infant to 3 was bringing bob strollers, pack n play ect.