First.. If you did not get owners manuals then follow this process
Go to a major RV dealer or Camping World and buy a book,, one of two (Either one) The RV Owner's Handbook -or- The RV Book
Both are generic owner's manuals and quite likely will cover all you need for the "House" and "Chassis" parts. (I mean all trailers are walls, Ceiling/roof, Floor frame and plumbing and wiring after all.. NO differnce save where they put stuff)
Now: For the appliances and such including Doors, Steps, Water system and parts of the electrical system (power distribution (Fuse breakr) Panels and convrter)
Google: Make, Model, Manual (Optionally ou may add the device type as in the example)
Example: atwood 8500 furnace manual
This should take you either to the Atwood support page or dirctly to a PDF
Download PDF
As for backing into a site.. Very easy however...... I can not teach you how to do it (Well perhaps hands on) I've been backing trailers since I was about 10 and some of the places I've parked 'em would amaze you... So for me.. It's easy.
(Growing up on a dairy farm has many advantages.. I know how to back trailers and .... Well I can't post the other one here)