Its hard to interpret what you’re saying exactly, but I’ll try my best to help answer what I think your question is.
If you’re looking to implement a triggered event when an object passes (or overlaps) the trigger proximity, then you need to open up your level blueprint → add an event overlap for your trigger and implement the proper reaction from it.
For a door opening, you can simply: add an event overlap with your trigger selected → then add a matinee event to open / close the door.
Hope this helps you a bit -