What year is it? There might be slight differences in equipment between years.
Having said that, you probably have a 3 way fridge in it. The controls are most likely on the outside behind the vent. There should be a switch for 12V, one for 110V, and a knob for propane. Only use one at a time. Only use 12V when hooked to your vehicle and running...it'll kill your battery quickly. Propane generally cools it more effectively and it doesn't use much. Keep in mind, it takes quite some time to initially cool it off, so you may want to pre-cool it the day before you leave.
I'm assuming you have a cassette toilet. It has it's own water tank so, if you're hitting the button and nothing is happening, it's probably empty (just pump noise). The fill is on the outside and the black tank slides out the side for emptying. Put chemicals directly down the toilet and not in the freshwater tank for the toilette.
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition