Start with ONLY the basics: food grade water hose, water pressure regulator, electric adapters(30 amps is almost always available), and a quality surge protector. Outdoor Chairs, basic cooking pots and pans, plates, silverware, condiments, food, clothes, soaps and shampoo, paper towels, napkins, TP (septic safe- NOT RV required) basic tool kit and go! Add any electronics/books/games you must have and go enjoy.
Take paper pad to start a list of desired/needed items. For me that would include that wine cork! Some items are nice to have but not essential. Remember that weight equals less fuel economy and if you buy a bunch of items you don;t really need, you have wasted money.
Amazingly, most areas have stores!! You can always make do or buy while on the road.