He has a 30 gallon tank with a large water bowl, a small tree (it was on sale, thought he might like it and at first he curled around it a lot but stays in his hide ALL the time now), two hides and the bedding is the chunky bark stuff. We are doing a massive reptile tank cleaning tomorrow and switching all of them (we also keep geckos) to coconut fiber bedding.

Any suggestions for how I can improve his habitat?

The lady I got him from set it up, and she worked at a reptile house so I assume she sorta knew what she is doing, but I am totally new to this.