I would say like some people: Go see a tutorial. But I'm gay if i say that, because it will be a stupid insult, so I,ll don't say it.
So if you didn't find how to create a door who works with the handle, i dont really know if it's that you want but try to do a door first, put a rotate button who is attahced with the door, you put like parent the anme of the door with the one of the button. (Put a rot door, it should be better
. )
So if my help wasn't what you wanted to know or it doesn't work tell to me. : :