Well, when I was 17 and a senior in High School I applied for and was accepted at the United States Military Academy at West Point.
During the school year I was more or less like any other college student. I wouldn’t say my experiences day-to-day necessarily taught me how to be an effective officer in the Army. I was provided with an excellent collegiate education taught by very qualified individuals (on top of that it was free.) The big difference between cadet life and that of a regular college student is your life is more regulated, you are expected to behave and act a certain way and keep yourself groomed and presentable. There’s also sort of a mini chain of command inside the Academy. You’re a plebe (Fourth Class) when you first enter the Academy and within your corps that makes you a Cadet Private. As you advance through your years you’re “promoted.” From 3rd to 1st class there are positions within each class which are leadership positions making you a higher “rank” than fellow classmates.
The summers is when I learned the most about actually being in the Army. Each summer you do something different. The first summer is the USMA’s version of Basic Training,. The second summer you go to Camp Buckner for field training and the 3rd and 4th summers you spend assigned to active Army units around the world for on the job experience and advanced training courses. I was personally trained in mountain warfare my third summer (some fellow cadets were trained in stuff like airborne assault.) And fourth year I was in a leadeship position overseeing plebes and yearlings in their summer training.