I am not familiar with that model exactly so I will generalize. You probably have 2 - 120volt power cords. I assume the 120volt breaker will have 2 sides, system 1 and system 2, one set of breakers for each power cord. You need both plugged in to shore power. If you have 2 AC units you will have 2 or 3 breakers on the 120V panel. Turn both or all 3 breakers on. I say possible 3 because the water pump that provides cooling water to the AC's may have its own breaker. The boat must be in the water for the AC to work and make sure you open the thru hull to the water supply.
You probably have a couple breaker panels. One for 120volts and one for 12volts. They should be labeled fairly well. Go through one at a time to figure out what each does.
Yes, there is a ton to learn on a cruiser. A lot packed into a small space, even though you may think it's a big boat, they cram a lot of stuff in them.
If you are new to boats you may want to ask a mechanic to go through some of the technical stuff with you but don't be afraid to ask questions here.
And if you are new to boats I suggest a checklist for things. Like when you leave the dock, turn on blower for 5 minutes before engines, prepare all dock lines, unhook power and water, and so on...