How much money
are you looking to spend? There are too many outfits catering from the luxury to the penny pinchers:
Boat bookings.com is one of the outfits
VRBO has a section for boats
Clickanboat.com is more affordable
Sailonline.com has a good tutorial for you.
With COVID, things are a bit dicey outside the USA. The FL keys will entertain you for a week, but if you want to fall in love with cruising and relative close to the USA then you cannot beat chartering in Bahamas
If you are still want to touch US territory then Puerto Rico
is not a bad choice. I have no experience in St Thomas or St. Croix but prices are probably double.