Do I have spawn an actor to use it?

I have a number of event classes (fireEvent, isLost) which extend base class EventBase which implements a EventInterface.

I want to have an array of events and call a random one. So the array is of EventBase type.

How do I add the events into the array? Should they be type actor and do they have to be spawned in order for me to use their functionality? It doesn’t make that much sense to me to spawn them as they don’t need any physical representation in the game.