welcome to the site!
hate to say it but i think you didnt start with the best odds though getting a fish from wally world
. But im sure youll be able to get him to normal, theyre hardy fish
i think you might want to get some sort of heater for the tank, i think most people keep their tanks between 78-86 (someone correct me if im worng). Also it helps if he has some sort of stuff to hide in, keeps the stress down (plants, little sculpture things, heck some people just use a little flower pot or mug)