I don't want to replicate Steven's answer, but I want to include images.
The correct answer is to use OnActorBeginOverlap, as you were marked to. If you are not receiving the correct triggering dispatch, it's almost sure that you don't have the correct layering configuration.
You can do that using the Collision subpanel in the Details panel of your object as is shown in the image from below. This also applies if you are trying to configurate the collision of an element inside a blueprint.
If you want to handle the event in Blueprints, you can do this, as described in the documentation
If what you need is to handle the collision from C++ and configure the layering, then you can refer to this page in the documentation, where you can find a good example.
EXAMPLE OF COLLISION MANAGMENT IN C++ FOR UE4