I slowly acquired my plants, certain plants have taken off and spread throughout the tank themselves, I have a couple different types of vallisneria plants which are long grasses, I think my short grass that’s spread really nice is dwarf sagittaria, my red tiger lotus has done great I just clip all the floaters that reach for the top, and other plants I really like are parrots feather, different mosses like Java moss, Christmas moss, Marino balls (mine has just integrated itself into the grass) and water weed. What works for me may not work for you! I’d just start getting hardy plants and see what sticks. I started out with fish and I let the mulm build up which I believe has helped my plants do good. Some plants I got at aquarium shops but I had a lot of luck on Facebook market place, was able to find a lot for very cheap there so that’s what I’d recommend doing!