As stated, you _may_ need to plug the shore power cable in to a socket (probably) located near the generator or in the cable storage compartment. Or you _may_ have an automatic transfer switch.
You almost certainly have two layers of AC circuit breakers. One or two on the generator, and two or three, maybe more, in the fuse/breaker panel. Those have to be closed to power any AC stuff like the A/C.
Manuals... as stated before, the factory manual was probably pretty generic & uninformative. But the RV when new would have come with a pack of individual operation manuals from the makers of the individual pieces of equipment used, like the generator. You can look for labels on the stuff to find maker's name & model number, then use Google to chase down the ones still in business and look on their websites for copies of old manuals.
X2+++++ on changing the brake fluid. It absorbs water from the air which lowers the boiling point. I changed the fluid in a Porsche 968 when it was seven years old, and let the old stuff settle in a clean jar for a week; over 5% was water. Had a better pedal feel, as well as more confidence in the brakes.
G'luck!
Jim, "Consider the Malevolent Universe Theory... it may really be out to get you!"