First, read through the general advice I give to anyone considering pursuing an appointment to a service academy. I’ve included links to the nomination process in that post.
It looks like you’ve already reviewed a recent USNA class profile. The snapshot does not list average GPA, but other sources list it at 3.75 which aligns with the other academies.
“Military-like” activities are not required to be an attractive candidate. (You get plenty of them once at an academy, no need to rush.) You must be extremely fit to pass the CFA, and almost all appointees are varsity athletes, so you’re doing the right thing there. Keep at it, earn at least one letter, and become a team captain if you can as that counts heavily toward the leadership score.
The academies are not in the business of producing doctors. Their mission is to produce capable officers for our armed services. Almost all military doctors earn their MDs from civilian schools and apply to the services for a commission later. The chance of being selected for med school directly from an academy is very slim. You will need to be at the very top of your graduating class (don’t discount this difficulty) for the three or four (or fewer) slots available for medical service in any given year. You go to a service academy because you have a burning desire to serve in whatever capacity that branch needs you. Also understand that the service academies are federally mandated to branch at least 69% of each class into a combat arms role. (USMA branched 81% of our son’s class of '19 into combat arms.) You are much (much) more likely to end up in the fleet from USNA than medical school. If you really want to pursue military medicine, USU or HPSP are places to start.
Apply to USNA because you have a deep desire to serve. There are more guaranteed paths to medicine from the civilian route.
If you’re still interested in applying to serve, this article discussing the 20 things you need to know about being admitted to a service academy is still relevant.
Any other questions you have about applying to a service academy can be found on serviceacademyforums.com, the equivalent of CC for those pursuing service academy appointments.