Please help! How can I improve my chances for Berkeley?

I'm in PRE IB as a freshman (in CA). I think you have a good chance taking a very hard schedule and have a good gpa. I think taking the IB exam would help a little. It sounds like you are very involved, idk if I recommend taking a sport. It sounds like you are very involved already and sports can take a lot of time and grades tend to drop. If you haven't done a sport your first two years in high school I don't think you would have a good chance of being good enough chance of being a team leader as a walkon junior(no offense-just don't think it would be easy you would have to be good). To me it sounds like you have done all the right things and I wish you the best of luck!!! =)