Tips on how to get a head start at a film director (preferably for Pixar)?

I have an extreme passion for creating stories, plots, characters and character development, etc. and my dream job is to work at Pixar. I really would love to be a director and possibly screenwriter. (Lee Unkrich is pretty much my role model. :]) I have heard going to CalArts is good for a animator who wants to work at Pixar, but what about someone who wants to go into directing? What things should I major in? Also what other things should I start doing at this point in my life to get me a head start. (I am a Freshman in High School.) I'd REALLY appreciate any advice/help. Thanks in advance. :)