I see you are in Florida... a hotbed for current AND past players. I'll bet you can find an ex-college/pro catcher that will work with your son one-on-one where the learning curve and progression will likely be quicker than at a camp setting. It also affords the opportunity for refresher check-ins, homework, etc. If the guy is local, there is a chance that he will attend an occasional game of your son's and give ongoing constructive feedback.
Meanwhile, if you aren't familiar, the "catching 101" series of youtube videos by Xan Barksdale are pretty solid, IMO. The visual of proper execution is better than any I've seen elsewhere and instruction is succinct and straight forward and apply to all levels.