There is also zip lining on the way to El Yunqe. If you are experienced it may be be too tame. If it is your first or want something suitable for a youngster then it’s a good intro to zip lining. There are great views from the platforms.
Bioluminescence Bay is near by in Fajardo. May be challenging for pictures in the dark from your kayak.
Old San Juan with its forts are great for photo ops. Seek out some of the older streets with colorful rows of townhomes.
In Humacao (which is not that close to where you are staying) I recommend Maragata Charters on Captain Matt’s Cat. He will take you to Vieques for some great snorkeling.
Definitely go to Richies Cafe in Rio Grande. The food is ok the views are spectacular.
Have a great time!