What do you mean by arrange? Organize the global variables? How do you place them in the Event Sheet? Or are you referring to updating the global variables? If it is the first, that is up to you really, but you can look at dop2000's post.
If you are referring to how to tell EventX to increase popularity and decrease success, that is a simple action in the event itself. System > Add To variable or Subtract From variable and choose what you want.
If your events are loaded at run time not hard coded in an event sheet, then best is to give them an "id" and when you load one at run time, check the id and based on that, reduce/increase the variable you want.
If you are referring to something related to UI, then that is a different matter and it is a matter of aesthetic and not something related to C3 unless you don't know how to create UI in C3.