Hello and welcome to the forum!

The mossies don't need any heating so roomtemperature should be fine. They do want things to climb on and lot's of water so an aquaterrarium is recommended.
You really need to get a bigger tank for him because even if mossy frogs don't move around alot during daytime they do when it gets dark.

As NatureLady said, don't mix these with other frogs. That's never a good idea.

I feed mine dubia roach nymphs but small crickets should work good too. Be sure to gut-load them for extra nutrition for your frog.