Assuming you maintain great grades, get a very high SAT/ACT score and continue your strong extracurricular activities, you have a decent shot. Unfortunately, the chances, even for #1 students, with great test scores etc. are still maybe 15 to 25%, depending on other factors like race or family background. Unless you are a recruited athlete, or Malia Obama, there is just no guarantee.
If you want to improve your application, work toward state and national awards and recognition in your areas of talent. Put together the best application that you can, and hope!