Hi bamagal611, welcome to Cruise-Chat! Is your son into water sports? Snorkeling/diving are great in Cozumel. Paradise Beach and Chankanaab Park are two of my favorites. Tulum is fabulous! The setting of the ruins is breath-taking. It is a bit of a journey to get there, but very well worth the trip. We did ours with a half day in Xel-ha where the snorkeling was incredible!
In Calica you could do the Xcaret Eco Park, your son may enjoy that. It has parrots, beaches, an aquarium. I'm sure that others will have more to suggest.
Best wishes and have a great time!