You can download a free example of object interactions in my porfolio: Object Interaction System - Nestor´s portfolio
There are other ways of communicating between blueprints, but for the “user interaction” the normal way is to make a raycast (line trace) each tick, for games where you can interact with multiple objects. If you are goint to just interact with some doors ocasinally, you can go your way.
PD: Using volumes with triggers probably will end with poor performance than making a simple raycast each tick if you have multiple interactable objects.
Grts,
- Nes