Research everything you can in high school. If you're going to college, you're going to be an officer. If you're not, you can enlist immediately out of high school (well, you can enlist any time you want...officers MUST have an undergrad degree). The Academy is one route, NROTC is at many schools and a full scholarship will save you hundreds of thousands of dollars, OCS is another route but you're in charge of paying for your education before you sign up.
Interview questions [1]
Question 1
The process wasn't all that difficult - you just need a really good high school GPA and record. Do as many activities as you can and make sure you're on the varsity team of a team (the military values physical fitness). Also, if you're a STEM student...you're more desired than anyone else.