Recommendations for a 10 day cruise to the Keys

[Swiss sailor]

I plan to go on a 10 day cruise from mid April to the Florida Keys. Starting point with a 40' SY would be Stuart. I have some sailing experience (Mediterranean Sea) but not in the Tropics or the Florida waters. The intention of the cruise is to get used to the boat, snorkling, diving and just having a relaxed good time would be nice as well. The boat has sufficient water and fuel capacity, AC and a generator. She draws 5 ft. and the mast height is 63 ft.
I'm interested in recommendations towards routing, places to visit, anchorages, marinas, places to avoid etc..
Thank you!
Marco