So much good advice above. I can tell you our now 3/C MIDN DS wanted this since 6th grade. The idea was due to me sharing our family history with USNA, but it quickly became his. He attended STEM camp and fell in love. It became his life's mission for the next 4 years.
Fast forward to the anxiety-laden junior summer and senior first semester during the application cycle. He put pressure on himself, he wanted to get in so badly. He had a Plan B, a 4 year Tier 1 NROTC but he was 100% all-in for USNA.
A few days before IDay we held a party to shave his hair off (Covid times, so USNA asked it to be done in advance). I could see his nerves. He was trying to enjoy it but now this decision was looming.
We talked about it. I told him he could change his mind. "No one will remember or care" in a few months, at all. I told him he didn't have to have all of the answers right now, and the beauty of it is this:
IF you think you want to be a Naval officer, there is no harm in trying. USNA has been carefully selecting MIDN for 176 years and they are really good at it.
IF it turns out you actually survive Plebe Summer (and I bet you do just fine) you will settle in and find your stride, with some stumbling along the way. You will question your choice, your lack of sleep, your academic work, your PT--- but you won't question the bonds you form with other shipmates who are in your shoes (just different sizes). You will get through it together. And with a sense of humor, you will laugh your way through it all (DS has had amazing roomies and I love listening to their laughter and silliness, some a bit macabre).
Now, summer training, the good stuff. The exciting window into your future. This may be where you get bit by the bug of being an aviator, a submariner, a surface warfare officer, or a Marine. OR you could find that it isn't something you can see yourself doing. AND THAT'S OKAY.
That is why the 2/7 signing takes place at the beginning of your junior year. You get to try on Navy life and grow. You get to accomplish things you never thought you could. You may fail at many things-by design.
Wasn't it Rocky that said, "It ain’t about how hard you hit. It’s about how hard you can get hit and keep moving forward. How much you can take and keep moving forward."
IF at the end of all of that time, YOU decide this is not for you, YOU get to say so. You simply don't sign your 2/7 contract. You walk away with 2 years of incredible life experiences, top-of-the-list academic courses (and transferable credits), summer training, mentors, lifelong friendships, and personal growth. AND no debt. No other college (besides SA's) can provide you with that.
Not a bad 'try on' period if ya' ask me.
All that being said, if you know now, stick with your gut. If you are unsure, the try might just be a once-in-a-lifetime.
The nerves are totally normal. And remind yourself, no 17-20 year old has all the answers, you aren't expected to know what you want your entire life to look like at this moment in your journey.