C# void names

First - to correct you on a bit of terminology: those are all methods. Specifically, they are methods of monobehaviour-derived classes, which are automatically invoked by Unity when certain events happen or at certain points of your main game loop. "void" is the return type of those methods. It means that those methods don't give you a result back that you can use in further calculations - they give you "void" (i.e. nothing) back.

Secondly, yes, there are lots more. Look at the "messages" heading in the Monobehaviour documentation: https://docs.unity3d.com/ScriptReference/MonoBehaviour.html