Welcome! I agree with what MoonStar wrote. Though, I must say that I think you will find full-timing in a pop up very difficult. First off, you won't have as much room for things, and while you don't need much, every speck of space counts! But more importantly, it's much more work for set up and break down. I remember as a kid we took a 2 week trip in a pop up. OH, the work! We always had to take out the coolers & suitcases and load those into the station wagon (yes, we had a station wagon! LOL!) Then we had to pop the thing up and out, then make the beds, set up the kitchen, etc.
When it was time to pack down, we had to do it all over again. And on rainy days, it was even less fun! You will spend a lot of time setting up and breaking down. And, what will your girls be doing while y'all are doing all of that set up/break down? I know what that would look like for us. I would be entertaining the girls while DH did all the work. That's not fun family time. Personally, I would never, never full-time in a pop up. But, that's just me. (no, seriously, I had FUN on our 2 week trip! LOL! I'm not damaged!)
I also agree - go somewhere warm. You will spend a lot of money on propane otherwise. And to me, the beauty of living in an RV is that you can follow the sun!
But, that's also more expensive because you follow the crowds and the peak seasons.
I would spend some time reading books about full-timing it. I got "Living Aboard Your RV" from the library, and it was pretty good.
As far as what to take, take what you use most already. You won't need many clothes if you do laundry often. We have a small washer/dryer in our RV, and I do laundry about every day. So we often wear the same 2 shirts over and over! I have a lot of crafts & books, some legos, dress up, & a few other "favorite" toys. I wish I had room for more books, and I wish I had brought more puzzles.
We have a huge cast iron pot that we use almost exclusively on the stove. Occasionally, when we want a 2-course meal, we'll use a second pan. We use our oven a lot, with our glass Pyrex pan. Figure out what dishes work in your RV oven. We also took 1 plate, bowl, cup, per person, plus a couple extra for serving dishes. We originally took only a few pieces of silverware, but it didn't take up more room to bring along more, and with the little girls eating all day, plus needing some for serving, we grabbed some more.
That's all I have time to type at the moment. If you have any specific questions, send them out!