I did not decide to join the Army until I was 18. Like everything else that I've done since then, I went into it blind. I was going to enlist, but my teachers begged me to go the ROTC route instead. So, I did. Being the only person in my family to attend college, I had no idea how to choose a college, pay for it, what to major in, etc. You know what? It didn't matter. A degree is a degree in terms of getting into the Army. Nobody in the Army will ask you what you majored in, nor will they care if you tell them. I never met anyone who cared about my major or where I graduated from.

When I was in high school, all I knew was that I wanted to be in the Infantry. My preparation for college consisted of absolutely nothing, other than taking a year off after high school to work and save money to pay for college. While in high school, I drank heavily, got into a ton of trouble, had awful grades (but good SAT scores!), and my extracurricular activities were just fall and winter sports. When I went off to military school, a lot of my peers had done JROTC in high school. Their only advantage was that they knew how to march around. Talk about a useless skill. You will learn everything that you need to know about the Army from the Army. Don't worry about trying to get a head start on it. You can learn how to read a map, use a compass, do terrain association, and estimate your pace count in a few hours in basic training. You don't need to figure it out now.

Looking back, I would have gotten into less trouble and drank less. Other than that, I see very little consequence to what occurs in high school. Unless you're trying to get into an Ivy League school or West Point, your grades are not super important. I think you only need to worry about two things.

1) Get in shape - focus on the basics of pull-ups and running. If you can do pull-ups, then you can do pushups. If you can do that and run, then you can probably do lots of sit-ups. That puts you ahead of the vast majority of your peers once you get into ROTC/Academy. You are young and enthusiastic, so you will probably want to put together some insanely complex and ambitious workout plan, but it really is not necessary. Pull-ups and running. That alone will put you in the 90th percentile.

2) Take a foreign language. I suspect your high school offers at least one. My advice is to take anything BUT Latin because nobody speaks Latin. Learn a language well. When you learn a language, you also learn about the culture that speaks it. The more you learn about other cultures, the more you analyze your own. Analyzing your own culture is the most useful way to understand other cultures. This process will better prepare you to interact with other cultures, which will be necessary regardless of what type of war we fight or operations we conduct. Plus, once you learn one foreign language, learning a second one is easier. This is one of the few valuable, practical skills that you can acquire in high school. If your other classes suffer at the expense of you mastering a foreign language, I say: so what?

Don't worry about choice of major. Your first two years of college will largely be core curriculum of more English, math, science, and history. You don't need to choose a major until you're halfway through college. Besides, you're only halfway through high school. Your interests will change.