Welcome to irv2.
Here is a Brochure
and Owners Guide
Below in my signature are links to many more for your Newmar.
In some of the QT's links your will find these to answer your questions.
12V BATTERY SYSTEM
---- Solar panel explained here end of link.
Any time you are using the coach have your battery cut off switch on
so Gen, shore power cord will charge all your batteries both house and the two chassis batteries with your Bird System maintaining them.
The house batteries may have been depleated by dealer for moving slides which should only be moved when the coach is plugged in or Gen running, motors for slides need a good clean 12v for motors to operate.
Motors are high torque please be careful and have slides clear behind them because serious injury can result. Here is a slide spec
for your coach. More slide info can be found in QT's 1 & 2.
One of the outlets maybe for your heating cord for engine block heater and a switch located in your display area or in bathroom.
Congratulations and welcome to the Newmar family and do join us in the Newmar forum.