I just saw the solar option for Landmark 365. It's a factory install option. Battery power goes through an inverter and a transfer switch to an electrical sub-panel located in the battery compartment. The sub-panel has three 120V AC circuit breakers that feed the residential refrigerator, the outlets at the living room TV, and the outlets on each side of the bed. This means that the trailer wiring differs when you order the solar option.
If you want other outlets active, you first need to determine what you want to run, figure out the power demand, and select components to deliver what you want. You'll have an entirely different set of components and wiring from what the factory option includes.
Several people on the forum have added large solar installations. They'll probably chime in shortly with advice.