I have designated a custom event called DoNewMotherShip and added it to the new Repeat cust. events on my mothership spawner but where do write the DoNewMotherShip code?
If DoNewMothership event needs to just spawn things, use TriggeredSpawner (on any number of separate game objects) to listen to that event (no code needs to be written). If it needs to do something else, you'll need to make your own class implementing ICgkEventReceiver, as mentioned in the readme.
I can't also teach C# basics too much, but here's a start: There's a KillableListenerSubclass in the example scenes.
Notice the following:
1) For a subclass, you need to specify the parent class on the class declaration line. 2) You override only methods that you want to change, or add new methods / properties. 3) Attach the subclass you make to a game object, then drag it into the "listener" field on a Killable. If you place it on the same game object as the Killable, then it will auto-hook up and you don't need to drag.