You will need a length of RG6 cable terminated with F-connectors. Just like the cable you use at home from wall to cable box. You can purchase pre-made length of these at Walmart and tons of other places.
GE Quad Shield RG6 Coax Cable, 25' - Walmart.com
Then you connect outside from the cable the campground provides to the side of your AS. Inside you should have a small black button on the cover plate behind the TV - make sure you press button and turn light off to disable the amplifier (used for the roof antenna). Then go to the menu on the TV and look for the area to search for CATV signals. Let it run through its process and you should be all set.