Class Blueprint won't Fire

So I’m completely new to Unreal so I had a few questions:

1.) For class blueprints, do I need to insert the mesh (from the class blueprint’s viewport) into the game for it to work?
2.) I want to do some general blueprints that don’t involve an object. Should I use a “level blueprint” for this instead?

I’m asking this because my class blueprint event isn’t firing at all. I’ve created a simple loop: press F key and the program loops through index 0-1. But if I copy the code into a “level blueprint” it works fine. Why isn’t my “class blueprint” working?

I hope this makes sense. I have a little understanding of Unreal, so I’m not sure how I could better explain my scenario.