Almost 
you got to call your dispatcher in your GameMode and everyone who Listens to that Dispatcher “Binding” gets notified whenever the Dispatcher is called. Like this as Example:
You also dont have to bookkeep your Score in more than one place. In the above example I send the score along but you could also get it from your Game Mode directly with a small modification like this:
Here a recommandation of a Training Video that explains a lot of things including Dispatchers very well. Its a little long but worth every second for beginners: Blueprint Communications | Live Training | Unreal Engine - YouTube
If you still got Questions left feel free to ask.