Editing vBulletin settings?
 

I've gotten so far that I know how to change templates ok..

..what I haven't figured out though is where do I change the pages in the adminCP??

Like the pages in vBulletin settings with all the fields to fill in, to control stuff??

You can't.
The admincp templates are not included in the change-able templates.
If you want to change them, you'll have to do it by importing xml files that include the changes. I don't know how that works, though.