My goal is to take as little as possible. Of course my wife's goal is to take everything we own. I would start with the essentials that you need to set up, cook, eat, and clean. As was stated, chocks, boards, water hose, gray water containment for the set-up. We started with disposables for eating before getting a dollar store set of plates, cups, and bowls. We have a cheap set of pots/pans along with a few cooking tools. We use the Lysol wipes to do most of the cleaning except for the cooking/eating items that are washed.
Also don't forget a basic took kit with some electrical tape and duct tape. Also make sure you have a lug wrench that fits your Pup's lug nuts and jack that will work. Some Pups can be very low to the ground with a flat tire.
Remember that storage space is usually very minimal in a Pup. I suggest at the beginning of every season for a few years, take everything out of the Pup and go over it with a critical eye to decide if it is something you really need. Unless it is something like tools or a first aid kit, if we didn't use it the last season, it is probably coming out.
Even though you have been camping a while, you may want to make your first trip close to home and a store. Once you determine what you forgot and what you need to buy, you can get them while you are still camping.