I concur with BUM. Let him have fun and learn how to throw strikes. Don’t pitch too much at this age. The only other thing I would add for this age is to learn “balance”. Learn to balance on one leg on the mound, learn to take a small step back at 45 deg to get started in a balanced way - staying over his center, have a balanced follow through. Many pitching related problems develop from the simple problem - a lack of balance. Beyond this it is too much and too soon.