Thanks for all of the awesome advice and ideas. If the trip goes well we plan to park up the RV over the US winter and return the following year to do Canada and Alaska. Perhaps parts of South America the following year.
We bought a "America is Beautiful" National Park pass.
As a shake down trip we spent a few days in San Diego and went to the zoo. We have just spent three nights in the amazing Yosemite national park. We are heading to Lake Tahoe today.
As a rough guide we are going to follow this route.
https://www.mentalfloss.com/...ltimate-us-road-trip As we get to each state we are going to work out what we want to see and plan a route through the state.
We are going to do it in the reverse direction to try and make to most of the warmer summer weather in the north and try and avoid busy national parks over the peak summer holidays. The southern states we will do as the weather gets colder.
Once thanks for all of the advice and ideas. I will include them in our trip.