This is a very personal list, my advice is to go to a campground within 5 miles of a Wal-Mart for the weekend. Pack the things you think are essential, when you realize you are missing an essential item (can opener, flash light, screw driver, blanket, etc.) put it on the list, go to Wal-Mart buy it (Wal-Mart usually has a fairly well stocked RV aisle in the automotive department for RV specific stuff). Repeat.
2002 Safari Trek 2830 on P32 Chassis with 8.1L