an enumerator is just a number that has a name associated with it.
name is just so that you can easily read it, instead of having to remember that 1 = left, 2 = right, etc.
To make a door open is really worth making a separate thread because it is a separate question from the title here.
it is good to only discuss just one small problem per thread that way people searching for answers in the future can easily find them.
In fact, I bet if you search “how to open door” you’ll probably find a ton of answers already.