My school is ranked 3,500 in the country, will that affect me negatively to getting into a top school like Cornell?

I must admit, having a 75 in gym might not look the greatest, but it shouldn't hurt you too badly. It's not a core class like Math or English, so that's good, but a C is still a C. A 97.6 weighted average is good, though, so great job there.

The 85 in geometry isn't too bad either. I wouldn't stress about it too much. I actually think that's what I got in Geometry. But keep in mind that right now Cornell has a 12.7% acceptance rate, and that number might be significantly lower by the time you're ready to apply to college. Having higher grades will give you a better chance of standing out among other applicants.

Don't worry about your school ranking. Most colleges, especially the ones with super low acceptance rates, have individuals who are experts in the types of courses offered and the academic rigor of the schools in YOUR area. They'll look at the courses your school offers to see whether you took advanced/AP/IB classes if you had the chance. If your school doesn't offer any of those, but you're doing exceptionally well in the classes it DOES offer, they'll take that into account. They typically don't judge you based upon where you lived or what high school you went to unless you were placed in said school for disciplinary reasons. That could change some things.

But like I said, don't worry about what school you're currently attending, and don't let a few grade slips totally freak you out. Worthwhile colleges have a holistic review process; they look at essays, extracurriculars, ACT/SAT scores, AND grades, not JUST your grades. I WOULD recommend trying your hardest to stay close to a 4.0 GPA if you want to go somewhere like Cornell. But, don't think that a non-perfect grade here or there will ruin your chances. Just keep doing your best, and it'll be reflected in your transcripts.