I’d love to see sea turtles as well. Definitely on my bucket list! From what I’ve looked into, you don’t need cave diving certifications to go on a cenotes dive assuming you would be with a dive master, they don’t take you through any uncharted or tight areas.

I’d highly recommend getting certified if you enjoy snorkeling! Breathing underwater takes a little getting used to at first but once you get past a few uncomfortable things it’s a whole new world to explore!