You are in a great position at this time: you have identified what you want to do after you graduate from high school... trust me, most of your classmates barely have a clue or an interest in something that is about three years in the future - so sincere Congratulations! Now, prepare yourself to take full advantage of the fact that you have made an early decision. Start studying to take the SAT and ACT exams starting this calendar year. Meet with your guidance counselor and lay out your course selections for the remaining years in high school so that you will be positioned to take the courses you should be taking. Take AP courses for chemistry, calculus, physics, and grammar/composition at a minimum, and ensure that you get geometry and trigonometry squeezed in as well. Try to get to USNA at least a couple of times, possibly via the STEM program and NASS... you need to know what you are getting into and thse are great opportunities to do just that. Be careful in selecting your ECA's that you don't go the shotgun route, but get into programs that interest you and offer you leadership opportunities. You are taking on a rigorous, demanding challenge, but it is eminently worth your efforts. Best wishes!