There are several different areas and you decide which one you want to be in when you register. One is without electricity and with generator usage. One is with 30-amp and no generator (unless the electric doesn't work in which all bets are off
) and the handicap area with electric (some people need 24/7 electric for medical equipment). We signed up for the electricity area. We go in with full water and propane and empty black and gray tanks. Sometimes a "honey wagon" will come through and pump out tanks for a fee. At FMCA there may be a card in your welcome bag and you sign up for the honey wagon. At places like Quartzsite the pumper truck roams around the different camping areas and you flag him down. Of course you still have to conserve fresh water 'cause it isn't easy to pull out your space to go get water!
The reason I made the comment about the 30 amp possibly not working is they have big pedestals and run electric cables out along a row of coaches. If everyone tries to use their A/Cs and microwaves at the same time, then the 30 amp might not be adequate. It really depends on the venue. We've been in places where it works quite well and others where it goes up and down a lot. It's always a good idea to have some kind of voltage sensor to alert you audibly to power fluctuations. If it happens a lot, we sometimes unplug from the electric source. This can happen even in campgrounds, not just at rallies.
Yes, most of us have RVs because we want the comforts of home. Trust me, we don't do without just because we're at a rally!
You just adapt some by, for example, using paper plates so you don't need to wash dishes as much. Even our fancy toilet with a circuit board can be adjusted to use more or less water!