Ok, Microwave and Fridge are not usually on GFCI likewise A/C
Check A/C on BLOWER only (Fan Only) do not select COOL, does it blow air?
Does Microwave light come on
Does Fridge Show A/C
IF any or all of the above are YES then you are getting power into the unit.
If all are NO problem is likely the breaker that feeds the outlet you are plugged into.. Lights, Water pump and Furnace all run on battery power.
Now, if you have power to the RV a test lamp is better than a volt meter but nobody makes a good one for 120 volt
Get one of those lamp socket assemblies with the two leads and a reubber thing you screw the lamp into , and about a 15 watt (no larger) lamp. Get some 18 ga wire (lamp cord) and make some probes (Easiest way is to slide a small dowel in half, or drill trhough it length wise, or get a couple of test leads from Radio Shack and cut off the banana plugs)
Extend both leads on the test lamp with the test leads, I like to solder the jointsm and tape well.. but twist and tape shoudl do
now probe CAREFULLY for power.. one lead goes on the WHITE bus bar in the power center (CAUTION DANGEROUS VOLTAGES PRESENT) Tough the other first to the screw on teh MAIN breaker (LIGHT BRIGHT = GOOD) then each branch breaker (Same) if you find one that does not light up.. RESET that breaker
Next unplug from shorew power
I have found many RVers have a few screws loose.. You just testes several of those, also the other screws in that box (White and bare/green) One of mine took over 2 full turns before I even felt the start of Resistance, over 3 to tighten... That fixed some problems I had.. There are other screws in the line as well on some RVs. I had one loose on my power "inlet" (where the shore cord plugs onto the RV) and another had six screws loose in his shore cord outlet (not all RV's have inlet/outlet Shore cord) the outlet fell off in my hand when we disconnected for testing., Brand new, Sticker still in the window high end 5th window... The owner was not a happy camnper.. (I'd have loved to be there when he returned to his dealer) We got him wired up.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times