Question for being accepted into college from a private high school?

I'm entering into my junior year of high school in the fall and I felt like it was time that I start preparing for the future. A lot of my classmates are obsessed with obtaining a GPA of at least a 4.0. I know that it will be extremely difficult to compete with them on a level where I can graduate in the top tenth of my class. I have a GPA of 3.80 with two honors classes. Next year, I will be taking Honors Pre-Calculus and AP Chem and a couple of other honors courses. Senior year AP Calculus and AP Bio. I'm looking at eventually doing Pharmaceutical and something in the medical field and I'm not sure what to do. It is important to me that I can get a scholarship, but still attend a top school. What it really matter if I graduate top tenth or quarter of my class? I'm almost positive that I'm in the top third. Say there are 70 students in my class, would a college really care about how I stand amongst my piers? I can very well see my GPA going to 3.85+ in the next year but I'm not sure if it's guaranteed. I have less than 60 community service hours, but I'm very good at sports (including soccer and basketball). How much different is it to get into a college from a private high school than a public one? Any help is appreciated!