I’m not quite sure what you mean by “how does it work with actor begin overlap?”
If you want to drop an item from your inventory (I’m assuming it is an array), you have to first in some way choose what array element to drop, get the actor from that element, (spawn the actor in the level?) and if it is a “stackable item” you need to lessen the stack amount but if it is the last item or a none stacking item you need to remove it from the array.
I’m no professional but hopefully my approach is fairly correct >.<