There is no such thing as an owner's manual!
What they give you is a folder with individual owner's manuals of the individual appliances for most of the appliances and installed parts. A/C, range/oven, furnace, fridge, and maybe others like water pump, toilets etc, but don't count on it. There is no manual to tell you how the camper is built and how to operate it. Manufacturers just makes way too many models and changes year to year to bother with such trivial information. You have to get the seller to try to tell you how to operate it, though a salesman knows little, or read each individual owner's manual or search the forum for the info you are looking for such as the 100 others who have asked the same question and gotten the same answer.
Use the Search function. it is an icon that looks like a magnifying glass. just type in search words and you will get a list of forum post that are what you are going to ask anyway.
good luck