Great advice.This spring you should:
-finish the semester with A's and A-'s
-take the ACT and SAT as many times as possible, aiming to hit 750/35 on math
This summer you should:
-get a job
-volunteer on your days off
-get in great shape for the CFA
This fall you should:
-Take >17 credits with the most plebe-like schedule possible, emphasis on Chem/Calc/English
-Improve on the CFA in every single event
-be the top ranked freshman cadet at your ROTC batallion
-Join clubs or a sports team, seek leadership positions
-End the semester with a 4.0
-Write an essay that demonstrates maturty, growth, and ability to thrive, not survive, at USNA
I was successful at accomplishing most of what I just described above. It was enough to get me in on my 2nd try, although I'm from a realtively non-competitive part of MA.
I would only add one thing. I know it can be difficult for college freshmen to get leadership positions, but this can be done with things like being a counselor / volunteer at Boys State this summer, being an adult leader at Sea Cadets, volunteering at Boys and Girls Club, etc.