You can do a OncolliderEnter/Exit. There are a ton of information if you do a Google search - “Unity opening a door”.
You can do the animation in Unity for the doors or you can do it outside of Unity. It is up to you.
So I suggest searching a little and watch/read some stuff. It might take a little bit but at least try and come up with something and then if you are still having a problem come back and post where your problem is.