The A-Frames have a 3 way fridge. You can choose which power source to use (only use one at a time). Most of us will pre-chill the fridge at least 24 hours before leaving using 120vac, then run it on 12v while towing to the camp site. Once at the camp site if there is shore power switch to 120v (turn 12v off, turn 120vac on).
If you are dry camping (no shore power) then once at the camp site turn off 12v, and light the gas for the fridge.
The hot water heater should only be switched on once you KNOW it's full of water. Here's a good thread on the hot water heater: Water heater on a Rockwood Hard Side
Also - there's a great thread where Rawlus has complied a PDF file that contains the user manuals for ALL of the potential appliances for our AFrames (Thanks Rawlus!): A-Frame appliances
(This link takes you to the last post by Rawlus with the final version of the PDF file - download it and save it to your smartphone if you have one, then you will have all the manuals handy if you need them).
Give the manuals a going over - ignoring the manuals for appliances you may not have. You should have received hard copies of all the manuals for your camper when you picked it up, if you bought it new.
2011 FR Rockwood Premiere A126 Hard Side
TV=2011 Jeep Wrangler Sahara 2 Dr
Reese 66065 WDH, Curt WDH Shank #17120
Prodigy P2 Brake Controller, Mopar 7-pin Harness
B&M Transmission Cooler (#70268)