I would take a walk around the resort to familiarize yourself. It's not a very big place, but you will want to know where the Mercantile is, where the recreation rental window is, etc. If you want to rent bicycles for your stay, this you can do it at the rental window.
Then I think I'd go over to the beach house and do the same thing.
Once you know your way around the resort a bit, you can look at the activities offered and see what looks good for you. The cast members will also give you some suggestions.
Be sure to pick up some of the island activity books and the restaurant guide for more ideas of what to do and where to go.
My overall favorite activity at the resort is relaxing!!