The fact that you have identified your interest in attending a service academy at this early date, in addition to frustrating you, also provides you with additional time to position yourself for your campaign to earn an offer of appointment to a SA. Meet with your guidance counselor and discuss your interest - take a parent if your counselor is a naysayer re the SA's. Do your best to ensure that you will be able to take the best courses available to prepare you for college in a Bachelor of Science program; ie, AP level courses in chemistry with lab, calculus, physics, grammar and composition, plus courses in geometry, trigonometry, etc.
Go to the admissions sites for the SA's in which you are interested and find your local liaison officer. NAVY uses zip codes to organize its liaison system, so locate your Area Coordinator and shoot off an email or phone call and identify yourself and explain your quandry. The AC will set you up with a contact person - may or may not be your BGO, but plugged into the admissions process - who can help you with your immediate questions and advise you of any events in your state or area that can give you more information on USNA, including congressional events, OPINFO midshipmen visits, college fairs, admissions forums, etc. Be sure your parents attend with you, especially if they have questions or concerns.
Another course of action for you is to apply for STEM now and NASS later, or check into
www.navysports.com for a sports camp of interest, any of which will get you to Annapolis to see the school for yourself. The Yard (campus) is open most every day of the year, except Christmas, and you can tour casually or on a guided tour. Also, Admission now is located in Halsey Fieldhouse just inside Gate 1 and it provides admissions briefs every day except Sunday - they are walk in.
Start planning to take the SAT and ACT exams in the next few months and work on taking them until you are comfortable that you have scored the best grades you can. As a guideline you really need to have your math scores at 700+ (SAT) or 30+ (ACT) if you want to be competitive. People get in with lesser scores, but the lower your grades, the more agonizing will be your waiting - in my casual observation.
I believe you are on the right track for this stage in your pursuit, but in the long run you really do need to get to Annapolis and see the school for yourself. Don't hesitate to ask questions! Best wishes to you... it will seem like an eternity, but it is a great opportunity!