Caitlin,
You seem to have the right idea about life and I suspect you have some idea what you are getting into. I think your best bet with Caye Caulker is leave most things behind you and to show up and find a room. If you don't like it, you can move on easily without much baggage. If you do like it, you can send for other things. If you don't, you can find another place.
To get into the long term, you should require a basic kitchenette. However, at the beginning, it should not matter all that much.
Have a great time there!