I learned the hard way with my first. I later got a 'idiots guide to rvs' for the second. The third was after enough experience to know what I was doing.
A few basic rules I know:
1. Unless it has residential appliances, don't treat it like a house. Such as never set the A/C to 65 if you like it cold, you'll freeze it up in no time.
2. If the roof leaks or has, you can guarantee it will always leak or leak again in a more inopportune time, such as your bed while you sleep. My current tends to have phantom leaks that move around or happen only once in 5 years and never do again. Been on the roof too many times to count and found nothing. Tried the hose trick and guess what? Never leaks during testing test. One shower and three lights fill up with water. Go figure.
3. Never turn the water heater on before the water is hooked up first. If you do you'll be operating on propane forever or have to shell out $650 for a new unit since mine didn't have a replaceable element for electric