Blueprint passing Question

This is probably a noob question, but I am having issues calling a event into a blueprint for a basic inventory system. I followed the UMG inventory from youtube and have that working but I wanted to try to make my own system and I seam to be falling short. Here is my logic so far and maybe you guys can direct me on what I am doing wrong.

I have a collision box in front of the character. Character presses “R” and it returns actors in collision like it is supposed to. My actor is a BaseItem. Everything works ok but I want to pass that Item information into another blueprint called Inventory. I tried using a interface but I call the message and I do not know what to put as the target for it to work. I tried making a variable of the object blueprint Inventory but it does not work. I am thinking that it is because I do not have the instance of the Blueprint Inventory. How do I get the instance of a blueprint that is not called in the level so that I can call a event to that blueprint?

P.S. I am at work on a 30min lunch break so I do not have a great chance to proof read this. I will put more detail in this post when I get home. Sorry for the confusion.

TL:DR
If my logic is correct. How do I get the Instance of a blueprint that is not placed in the level so that I can call a interface event to it?

I still would like to see if my logic was correct if someone could answer. But I cheated and bought the inventory system on the market and I will reverse engineer it :). So no big hurry.