Great advice from all above. Our DS is a 2024 Plebe to be and he knew from 6th grade what he wanted his end game to be. As
@justdoit19 said, sit down with your counselor, if at all possible plan out all 4 years of courses. Our DS met with counselor, she was aware of his goals and they reviewed the recommended course work for SA's. They plotted out 4 years and together reevaluated it at the end of each semester.
As
@Devil Doc said, do not be a follower. The kind of young men and women who get into academies are not followers, rather they are leaders. I won't say our son had a whole 'lotta fun in high school, he was working hard and had little to no time for social life. But he chose that, and made peace with it.
When his 8th grade friends started making poor decisions during that summer, he cut all ties. There is not room for using, abusing, partying, making social game more of a priority than your grades and your future. It may have felt lonely at times, but he says it was worth it. He and others on this forum had many incredible options on the table because they put in the work.
Don't look at how you manage four years. Think of it this way...how do you eat an elephant? One bite at a time. You have a big picture goal but a one bite at a time mentality (never would I actually suggest consumption of a real elephant).
Manage your time, keep a list of to do's. Maybe a white board with meeting dates and times, assignment due dates. Seek teachers and others who are positive mentors.
Write down your goal. Revisit that page. Have a positive attitude. Expect success because you can do the work and keep your head down and pushing forward.
You have an advantage of starting early in this process, good luck to you!