There is a store to the left of the resort, as well as a larger store down the street further or the gift shop in the lobby of the resort for snacks and small items that you may have forgot. It's best to bring as much if your own stuff as prices can sometimes be more expensive then what you would pay at home. Walmart is only a ten minute bus ride from the resort, it's good for cheap alcohol and to stock up on red bulls to have at night tie to it with your drinks as it is more expensive at the stores near the resort. It's a nice way to break up the day if ya wanna get away from the resort for a bit.
