Your CFA will be REALLY important since you're homeschooled and indicate you have no athletics. You can practice the elements of the CFA and the CFA itself on your own. Start NOW, so you can take it for real in the summer and be done.
If you can do any type of organized sports, I encourage you to try. Depending on where you live, it may be very hard during COVID. But, if things open up this spring / summer, look for opportunities, such as city / county leagues, Catholic youth leagues -- anything. It's not just the athletics, it's being a member of a team.
In addition to the above, developed a formal, documented workout plan for yourself. Suggest you model it on the plan they give soon-to-be plebes to get ready for PS. That demonstrates you take fitness seriously, not just kind of work out when you feel like it. You can discuss this plan with your BGO.
Agree with looking for leadership opportunities. You do NOT need to be elected to something. As I've said many times, start with an activity about which you are passionate. Find an organization that supports this activity. Join it. Then look for something the organization is doing that you can lead or come up with your own idea. Alternatively, come up with an idea outside of a formal organization.
For example, are there elderly people in your neighborhood? Could you arrange to mow their yards, weed, paint the outside of their house, plant flowers, repair their fence, go shopping for them (leaving stuff on the doorstep)? All of these are COVID-safe and demonstrate leadership. Can you get a bunch of people to bake home-cooked food that you could deliver to a local nursing home or assisted living facility (you would not need to enter the facility, just drop off stuff at a distance). Are you into art? Can you set up an on-line art show or auction with local artists? The possibilities are endless -- just requires some ingenuity, drive, ambition and maybe elbow-grease.