What should a Sophomore in High School be doing in order to be competitive for getting into the United States Air Force

If your school has an ROTC program, make sure to put a lot of time into it. This is usually the beginning of the military experience and the Air Force Academy wants candidates that are passionate about serving. If the 4.25 is out of a 4.0 scale, you have no to worry about on grades. 4.25 is excellent. However, if out of a 5.0 or 6.0 scale, try raising your grades even by just a little bit. Your grades are not low enough to worry about, but it is still imperative to try and get them as high as possible. If there is clubs in your school such as NHS, do everything you can to get accepted in. Take harder classes, possibly AP, IB or Honors and make sure you are confident but not arrogant. All of this will show the Academy that you are ready and that you belong. I'm not an expert, but I hope this helped!

Like @Amelia17 said, if your school offers an Air Force ROTC you should look into joining that so you can get some experience on what to expect. While I know you're only a sophomore, the Air Force Academy also has a summer program for juniors heading into their senior year. It's highly competitive but the good news is your application won't be impacted negatively if you aren't accepted. When the time comes you should look into applying since it will give you a good sense of what to expect at the Academy.

Also consider signing up for their future falcons program which you can find here: https://www.academyadmissions.com/prepare/middle-school/falcons/. You'll be able to stay up-to-date on admissions changes and will receive invites to any outreach events in your area (which you should also attend).

Other general things you should consider are staying active (join a sports team or club if you haven't), holding leadership positions, and building character through organizing events and helping out in your community.

For more info on how to prepare check out this link: https://www.academyadmissions.com/prepare/high-school/

To check out the requirements and see where you stand currently look here: https://www.academyadmissions.com/requirements/

Best of luck!