Hi there, enjoy your new (to you) camper!
You will have more feedback in the "Truck Camper" subforum - maybe post there again, or ask a mod to move your thread. I stumbled upon it by accident.
There is very likely no such thing as a single manual for your camper. And if there was, it would be very generic. I did not get one with my N* when I bought new.
What I did get was a bag with manuals for the individual appliances.
These can usually be found online when you google the manufacturer + model + "manual"
A good starting point might be bryantrv.com, they have an online collection of manuals.
Other than that, just ask specific questions.
2014 Ford F350 XLT 6.2 SCLB + 2017 Northstar Arrow