Here’s a video that attempts to explain one method for driving on a very dry, slick track. I think you should probably work your way up to this from a very wet track. Learn to drive a very consistent, competitive line on that, then decrease the wetness gradually and learn how to change your line for each condition.
The main focus in the video centers on how wheel spin can slow you down on dirt. That’s something I have not figured out myself yet so I can’t elaborate on it other than to say that when tire wear is activated, we’re all going to learn a lot more about wheel spin.