If you have camped in a trailer or motorhome before, a lot of the information will be redundant. What you want to focus on is things that are unique to the coach you are buying. Video, notes, sound recording, whatever helps you remember is OK.
The best thing to do before you leave the dealer (see if you can stay a few days) is try everything with a switch or a knob and make sure it works and you understand what it does.
Good luck on your new coach!
Roger & Mary
2014 Tiffin Phaeton 36GH
2012 Honda Fit toad