Most owner's manuals don't contain much of the info you seek. You can go to many current manufacturers and download or read owners manuals to see. Owner's manuals are expensive to create, and many things aren't documented when production changes are made. To say they are generic is an understatement of generalization.
I always suggest you search your RV from top to bottom, poking into every closet, cabinet, and compartment. Note down any make and model number of any component you find, also noting any fuses or breakers you discover. Then use Google to search for manuals, troubleshooting guides, etc. for each of those items you found.
I also recommend pulling each fuse, then seeing what isn't working, replace the fuse, and pull the next one. Do it for the 120v breakers too. You'll develop your own 'map' of what items are on which circuits, information that can help on a dark and stormy night.
Enjoy your exploration of your new home!