That is a really good question. I will try to answer your question with a recent story!
I just got back from a visit to my daughter's house. The situation was somewhat odd. I drove my old flatbed 2400 miles to deliver it to my grandson that wanted it, with plans to return via economy flight, after the long awaited visit!
I planned for a week or two as to what I should take, knowing what I took would not get the round trip treatment.
Simply put if I could do without, I would not have to replace when I returned.
When outfitting an RV, it is wise to go through the same mental exercise. Weight will always be an issue! Clutter makes one feel closed in. The feel good purchases often associated with a new home, are usually disposed of soon, while realizing what you always knew!!! You didn't need that "junk".
Eat out!!! Yes for every meal. While you sit in your empty nest, make your check list, or go over the one you already made up!
Yup should have bought that coffee maker! Well an inverter might be nice, rather than a stove top maker.
Oh yah, I always pictured a camp fire, and the FS has a ban, guess a propane fire place needs to be on the list.
It was cold last night, would have been nice to have a throw while we sat on the loveseat.
That battery sure didn't have enough power!!!
You get the idea!!! Only you can figure out what makes camping, camping for you! The local big box can sell you those things you must have on the first trip or two! Shake down cruises are not just for the RV, they are for the campers equally. Put what you think you need from your household supplies, and confirm your needs as you live your dream!!!
Most importantly! Make your trips adventures!!! Nothing is perfect, your memories are what makes it so!!!