Im guessing that would be a 20 gallon tank then. Any particle bedding/substrate is a risk to their health and can kill them fairly easily at any age so good thing your using reptile carpet. Guessing you mean you have a MVB which produces heat and uvb, the reptisun uvb tube is an amazing bulb, however if its a t8 it will need to be placed inside or if its a reptisun t5 5.0.
I'd stop with the mealworms or at least only give him them occasionally and try to feed as many red runners as he'll eat within 10-15 minutes each feeding. As for the kale only feed that occasionally, its not the best honestly, try to give him collard greens, turnip greens and mustard greens. At that age eating a variety of insects is best and as many as he wants depending on the insect.