Go into the character BP viewport and add in a collision object as a child to the camera and size it to be about the cameras size. Then change a few settings on it so that the collision object can trigger overlap events and be sure that the objects you want it to overlap or trigger are large enough to reach where the collision object will be floating… being its on the camera. Seems a bit strange to want the camera to trigger overlaps though being that youre in first person, what would the difference be if it was the camera or the actor itself being they are both going to be in the same spot at the same time at all times. Care to elaborate on what the goal is?