Newbie question about plugging in at the house

We are in the research mode to purchase our truck camper. But I have a question and hope some of you seasoned tc campers can give me info? With the correct adapters, how much can you run when you are hooked up to a house with 20 amp service. I am looking for how many items can you use? AC, micro, stuff like that? We are hoping on camping in family and friends driveways and yards and I just want to know what to expect. Thanks