When you read Ellis, it's generally better not to even let your mind wonder what's "true" and what's not. Don't forget American Psycho. Remember how confused people were/are about whether Patrick Bateman was "really" doing all that killing or whether it was just in his mind. My answer to the question is always: First, it's a novel. No one is "really" killing anyone.
So that's a funny edge to be teetering on as you read, but and now I can't remember whether he claims Camden College in Lunar Park or not, but remember that Camden doesn't exist. Just assume that none of it is true and you'll do fine, lol.