Middle mouse button on top down style?

Hello guise,

I’m making an MMO with top style, point to move/interact and camera functions close to games like RuneScape and Knight Online. The camera should be rotating and tilting in when holding the middle mouse button and moving the mouse in certain directions as this is my exact goal…so I was basically told to do this:

So far I have gotten here:

Now my problems are as followed:

I am unsure if I’m even in the proper location due to nothing even taking effect.
I do not have a “Mouse X” node and have searched high and low for anything similar.
I also have absolutely no clue what the bottom titleless box connecting to MouseX is or how to implement one.

I’m used to C++ and not so much to blueprints. I am an ex Java platformer and am trying to expand to UE4 so everything is brand new and exciting to me.
I would love some help with this and I apologize if this is in the wrong sub-section.