Cornell University help?

I am going to high school next year and my dream since, hmm i don't know, a long time ago, has been to major in physics at Cornell. My dad went there and I just love it. What do I need to do in the next 4 years to ensure my acceptance? Grades, extracurriculars, volunteer work, etc... I will be in the marching band *fantasizes about drum majoring <--not a word* and NHS, science olympiad (I was on the state team in jr. high) and an astrophysics class. Hopefully I will get an internship at NASA in a few years. Just give me pointers por favor! Gracias! :D