It will vary from campground to campground. We just did a 4 week trip in the Aframe and had 4 way to do it.
The dump station, It normally has a cap that you stand on that will pop up, and somebody will have left a stone to prop it up so you can pore into it, there is also running water that you can use to wash the tank out, figure on getting your feet wet.
Then there is dumping in the head. In one CG we were instructed to use the head.
We use these two above the most.
Then we had one CG with a room between the men and women head, a big sink that flushed that you dump porta potty into and flush and there was not any other water. Then we had the same set up with running water that had dumping in it and then we had the same setup at another that was for dish washing and no dumping.
Then there was a dish washing area that had a big drain in the ground that we dump grey water into. Then ran water to make sure it was clean when we were done.
So as you can see you will need to ask or see what other are doing.
We are normally in CG that have some tenter and not to many of the big RV, So KOA type CG may be different.