Best way is to rent a car honestly. But, if you're tired that first day (we come from the East Coast so are often up for almost 24 hours by the time I get to bed that first day), you could just walk over to the market across the street for a couple things for breakfast, then rent the car the next day.
Without a car, though, how will you go out? You need a rental car unless you don't ever plan on leaving the resort. We always get one at the airport for the whole time.