It’s great you’re seeking out this info now!
If you can, see if you can find someone who dropped out of a service academy to get their perspective. Many do, and while their reasons vary, there is often a general theme of “I didn’t fully appreciate that it was going to be so _____.” If you know anyone at a service academy now, they know someone who left. Great place to start. Unlike other schools, these don’t focus on retention. Instead, they use the experience to further screen for what they deem important.
Also, the service afterwards can feel loooong. You should think about the time in school + commission and think about how much of the life you have experienced that it represents. If you are thinking you can make it through, be realistic about how long of a slog it will be if it feels wrong/uninteresting/etc.
I’m not trying to dissuade you, although it may sound like that. I’m offering some perspectives through which to gauge your true interest. There are few people for whom this is ideal, and they are a subset of the ones who believed it would be ideal for them. Otoh, for those who found it ideal, they got an education for and a launch into the organization of their dreams.