It is really easy. Last October we went for a long weekend and it was our 1st time without a car. The airport was easy. Get off your plane and follow the signs. Go downstairs and find which resort you are going to, give them your name and go wait for your bus. There was a bus when we got on line but it was full, we waited 20 minutes for another to arrive. We boarded and off to the resort we went. Got to checkin, found our room, went to the pool and had lunch. When we went back to the room our luggage was there.
Was nervous about getting around and relying on the bus system, but it was great.
My only piece of advice, is DON'T miss the bus they assign you when you are leaving. You can always try for an earlier bus if they have space, but they charge you extra if you are late. Also know the bus starts loading at that time, it doesn't depart until it is loaded. We had a 3:3o departure and my son left something by the pool and we were sweating we were going to make it. We got there at 3:29 and everyone was standing around. They didn't start checking everything until 3:30.
Enjoy!