What should i do with my 1 gallon tank?

I have a 1 gallon tank thats round but has two flat sides. I originally had isopods in there but they're now in a different enclosure and the tank is empty. I was thinking filling the bottom with sand and maybe getting a shrimp that wont get big or maybe a snail but i don't know if id need to set up filters for those guys. Id probably put some aquatic plant in there aswell, id imagine the plant depends on who's in there. I don't know much about aquariums but I think it would be cool to study whatever ends up living there and ill do all the research before i get them. My room gets pretty warm due to my lizard and their lighting so if anyone knows any shrimp or snails that are tolerant to warm temperatures please let me know, i dont want to get a pet and them suffer because the temperatures are off although the properties of water would make it not get as warm i think.