You basically have I-40 to come back on. You surely have some kind of time frame to hold to I assume so the meandering of the back roads especially through AZ and NM would be, lets say difficult. The issue of possible mechanical problems might make you stay closer to the interstate and larger towns in case help is needed. Tires will be the weak link. Are you ready to spring for new ones to get home on? If those tires have been baked in the AZ sun and are old to boot be prepared to put new ones on. Setting up and breaking down is not that complicated but don't forget the things like the TV antenna, don't leave it raised up when you depart the campground. Stow things well to keep them from moving around in the trailer when on the road.
Should you have questions at a campground there are plenty of helpful fellow campers that would gladly help you. Don't be shy, campers are a friendly lot. Google Maps and Trip Advisor are very helpful to find things to do along the way. Do get off the interstate when you can and have fun. There is quite a lot to see that isn't that far off the interstate.
RVPARKY app for your phone is great for locating campgrounds along your route. I would not worry about reservations. We start calling about 2pm with a good estimate of where we want to stop at around 4pm. We call the campground and check if they have a site for one night and then we will have them hold it for us. We have never been shut out with no place to stay.
Good luck and have a great time.