Stay off CC until junior year. You want to experience high school as more than just a prep for college. You'll have a better idea of the colleges you want to attend later on. A lot can change in 4 years. Don't worry about colleges for a while. Just work hard and have fun.
That said, the people I know personally who were accepted to Harvard include a 4.0 state saxophone soloist winner and a writer/literary author and editor.