Some could be taking AP or college courses online. They could also be winning contests or awards online. They could have parents who are alumni. All you can worry about is the things you can do for yourself.
Long before there were computers and internet, I lived in a small rural town. Kids from my high school went to Harvard, MIT, Middlebury, Notre Dame. Most did not (either didn’t go to college or went to state schools), but a few found ways to distinguish themselves.