As I see it you need to do 4 things:
1, Preventive maintenance and repair, check the age on the tires (replace if DOT date code shows them over 7 years old), if you don't have a good maintenance history change all the fluids (not just oil, but everything, power steering fluid, etc.), inspect for common drive train and suspension issues, battery condition, etc. Check for any rubber components that may have aged out, lots of these tend to sneak by, generally anything made of rubber will need to be replaced after 12-15 years max, this may include things like the fuel line running to the generator, or the propane regulator which has a rubber diaphragm.
2, Familiarize yourself with the RV, know what all the switches do, learn how all the systems work, how to hook up water, electric, how to dump the tanks, know how big all the tanks are, testing for correct function and repair when you find a problem is part of this as well, driving down the road in the middle of nowhere as the sun sets is no time to discover that the high beam headlights don't work.
3, Provision the coach, this is where some shake down trips / driveway camping really helps, though I think a local campground near a Wal-Mart is probably a better option than driveway camping. Again the middle of nowhere is not the time to realize you have plenty of canned food and no can opener, or that your drinking water hose is too short.
4, Education, watch RV videos on youtube, participate on the forums here, learn all those little tips and tricks, ranging from trip planning, finding campgrounds, to DIY repairs. Being able to fix stuff yourself, even simple stuff can make the difference between having a miserable time vs a minor annoyance. I don't think I have yet to go on a trip where nothing broke, on our last big 3,000+ mile trip these things included the passenger side power seat (broken power lead wire), the furnace starter short cycling during an early season arctic blast (bad over temperature switch), and a hydraulic fluid reservoiur started leaking (crack in the plastic). Any of which could have led to a miserable experience if not for my ability to diagnose the issue, and either repair it or come up with a work around.