Before leaving on an extended trip we don't worry too much about food. You aren't going to pack 2 months of food so pack enough food for a couple of days. Supermarkets are everywhere.
But do think about things you may need while on the road that you depend on at home. Computer, tablet, WiFi hot spot, books, printer, paper, guide books, kitchen utensils like blender, coffee maker, waffle maker, pots & pans, fan, portable heater. This kind of stuff you have at home would cost you unnecessarily if you forgot to take them.
Tools. A basic took kit is a must. Things on a RV break and it's not always easy to find someone to fix them. Basic spare parts like a fan belt, oil, transmission fluid, a step stool or ladder, etc.