Your odds are pretty good. Grades are not the only factor considered for students. In my opinion, grades don't represent ability but a cross between what is being taught, your understanding and the way a teacher teaches. It is a known fact that people learn in different ways and there are tests that you can take to make sure you excel in college by determining how you learn. Most colleges have entrance exams and would help you. Don't be so hard on yourself-you might not have all A's, but doesn't your school require you to meet a minimum standard to remain involved in activities?
Well... the fact that you are involoved in a lot of clubs helps your chances slightly, but your grades are definatly the MOST important part of your transcript. Do well on your SAT or ACT, get involved in sports, and exceed the community service requirements, and your GPA will be less important. However, if you have a 2.8 and want to apply to a university, forget about it. The competition these days is INSANE. My best advice would be to apply to a state college. Best of luck, college is the most rewarding and exciting time of your life!