What experience do I need?

So I’m a Sophomore in High School. I’m pretty smart I think, 4.1 GPA with all A’s which I’m not worried about. It’s the experience that I’m worried about. So in the summer I signed up for Havard MedScience, which was a week of shadowing, meeting and listening to doctors and other researchers at MGH and Brigham and Women’s. But since that, I’ve read online of people shadowing for over 200 hours? I only shadowed doctors for 2 days! What type of experience in internships, shadowing, and... What experience do I need?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums