They allow one camping vehicle and one passenger vehicle per site.
Our RV is a 20 foot long Class B (aka Van Camper) and I tow a 15 foot cargo trailer for our electric car (glorified golf cart) and "stuff". We always rent a minivan and never have a problem. My advice is to back up as far as you can on the concrete pad just before the rear wheels go off. (In our case with the cargo trailer, we unload the car and park it off to the side then back the trailer off into the sand pad and back up as far as we can) Also stay over as far as you can to the driver's side of the pad as you can. This gives you the most room to park the van, kids bikes, open the awning, etc. and is closest for the electric, water and sewer connections that are always on that side. Some pads are shorter or configured differently than others but generally will handle a motorhome and another vehicle.