Nice savannah but you need to fix a few things or in time you will have a savannah that will slowly die.

First take all that stuff out of the cage and put a good 6-12 inches of dirt, make a solid top to replace the screen one so the cage will be able to keep the humidity and heat in. Buy a temp gun and get its basking spot to 130F + as its import for them to properly digest there food.
You should be feeding him every day to every other day depending on whether or not hes hungry and try to feed small meals not large ones. Then as he gets bigger (3ft) you will only need to feed him 2-3 times a week as they are not in their growth phrase.
You can feed him pinkies or even try baby quails if he can eat one yet. If you want to keep insects in his diet in the future i would suggest you look into lobster, dubia or Madagascar roaches
The roaches can be kept in a large been with temps ranging from 80-95F, the warmer it is the quicker they breed and there a good supply for food. You just got to let them sit for a good month before start feeding them off and you wouldn't have to buy insects anymore as well.
heres some Madagascar hissers they get around 4 inches full grown, my supply is low as i had to start feeding them off almost right away as i ran out of food and all my rodents and birds weren't coming for another week.



Bryan