If I can add:
Find things you really passionate about and let that be a big part of who you are. Music and Crossfit were the things my DS was really in to- showing that you are as much of a three dimensional person as you can be is a big deal.
Also, be the kind of person people want to be around: be able to hold up your end of a conversation (but not necessarily become the WHOLE conversation.) Be fun and interesting. As far as I can tell, the academies are looking for the kind of people who make the greatest leaders: look at some of the most successful politicians and business leaders- people GRAVITATE towards them. Be able to make a joke...but be able to take a joke as well. Make sure you have a great handshake- not too firm, not like a dead fish. All these little things add up to BIG impressions when you have interviews and meet with your ALO. I know this always comes off as a little hippy-dippy; and, don't get me wrong, academics and test scores and leadership are all jobs ONE, but being well-rounded is a really big deal.
Best of luck! Keep us posted, use the search feature here, and never hesitate to reach out on the forum or in messages if you have specific questions! You got this, we believe in you!