fmf421, welcome to the forum.
We need a bit of information to help you out.
What chassis do you have?
Ford E-350, E-450?
Power Center - I have a 2006 Sunseeker 3100 with the Ford E-450 chassis and the power center is in the back of the coach in the bedroom, below the right side of the bed. If it is there pull the cover down and you will see the circuit breakers and 12v fuses.
Just to make sure, did you happen to plug the cord into a 220v outlet? That has happened to a couple of people on the forum recently, with expensive results. Hope not.
LP gas, I turn mine off between trips and only turn on right before we leave. I don't want to lose any to a leak (none so far).
Don't try the water heater until you have filled and "burped" it by lifting the relief valve lever and letting it reseat. You can get to that by removing the outside cover from the water heater. Make sure the water heater is not bypassed, there might be a valve on the inlet line, make sure it is lined up to let water in.
Refrigerator - Look inside the door frame for the nameplate sticker. Like mtnguy said with a make and model you can use the google to locate most of the manuals. I posted a set for my 2006 the other day here and they might help:
2006 Brochure and some manuals for Sunseeker
Do you have a battery installed for the coach (not the chassis starting battery)? This would be in a separate compartment. You need good 12v either from the battery or the converter (need 110v to get that) for the fridge to operate on LP gas. Do you have a battery disconnect switch and is it turned on? Mine is located just inside the door at the base of the cabinet. Without 110v plugged in and the switch off I do not have 12v power to anything except the slideout.
Let us know and we'll try to help.
Chris in Virginia