[Amygdalas]

This sounds stupid I know, but I hope for a serious answer. D:

Say I know the cause of autism at its base roots, what causes it and how it may be prevented.

How would I share this information with credibility?

I'm 18 and graduated with a 2.0 gpa. >.<

[Perna]

If I thought I had learned something I wanted to share I would get a doctorate in an allied field and put in my 10 years study/research with as wide a base of those I could (autism is a spectrum disorder, not a single entity, so probably does not have a single root cause) and become a professional in my field so I could get other professionals who have been studying in my field's attention and show them what I had learned (write professional journal articles, etc.) and prove to them it is true from my research.

Perna's right. The only way is to attend university.

If you wish to attend university, a 2.0 GPA is not high enough for admission. You will need to upgrade your high school or enroll in a junior college program that prepares for university education. The minimum average you should strive for is 70% or a 2.8 GPA. Some universities require higher GPAs, especially science programs.