The South Point is about 5 or 6 miles from the strip. I would suggest that you get a rental car.
They do have an airport shuttle. http://www.southpointcasino.com/hotel/shuttle-schedule.php
I heard they have shuttles to the strip too but haven't looked into it.
There is an outlet mall on the south side but you will need a car to get there. I would call the casino and get more information on shuttles.
There are several Walmarts on the south side for those that want to stock up on drinks, snacks etc.