Since you are new to the game and seem to have several projects in mind, I might throw in some info on sites to check when starting new projects as RV tend to be very confusing on the electrical and which parts to look where.
First thought to mention is the batteries as they tend to be one of the most frequent problem areas. The way we tend to use RV, makes the batteries much more a problem area if we don't get in and use the RV frequently.
In our car, we tend to get in and drive them to keep the battery good but when we store an RV, there are "parasitic drains" which do run the batteries down given longer times between drives.
Keep in mind that the battery disconnect switches DO NOT disconnect several safety items like CO and propane detectors, steps, etc. on the coach supply and there are things like radio presets on the start battery!
So when you buy an RV that has been on a lot for a time, there is a good chance the batteries are damaged or totalled!
Second point is that the RV being plugged in may get the coach batteries charged, even boiled dry, while there may not be any charge at all to the start battery, so watch carefully until you find what YOUR RV does. Not all work the same!
Wiring?
https://www.winnebago.com/Files/File...ram/Wiring.htm
Plumbing:
https://www.winnebago.com/Files/File...m/Plumbing.htm
Parts:
https://catalog3d.winnebagoind.com/menu/Parts.htm
Don't skip over the parts too quickly as it can help locate and help spot how to get things apart!