So let’s see here. Where do I start? So let’s look what I have access to. I can access various properties of Owners and the World itself, which let’s me create interactions between us (the Pawn) and actors of the game (for example the chair). Great! For that I’d use a component as I’m not very used to inheritance in UE4 (though I use it in vanilla C++). How would I know what to grab? Well I’d obviously first need to know the distance between a grab-able object and the current view angle of the Pawn. If both are good then when I send out a signal (by pressing let’s the good old “E” button) to grab the object it should be grabbed. Sending out another signal would release the object to FALL on the ground. That also means that there will be a variable to track whether I’m in holding mode or not. Obviously I’d have reconfigure the code that the actor that opens the door would be the chair. I believe that is all? There might be problems with the process of picking up the object itself without crashing the game, but hey that’s why I’m learning! 
