He's literally a high schooler?
Tell the poor kid that while GPA matters a ton in admissions, he shouldn't panic thinking that his dream is ruined at the age of 15.
On the other hand, if he's a real screw-up, it doesn't bode well for his future success in college.
Yeah, this is terrible.
I know so many people who were super allstars in high school. They never had to study, they could get their homework done right before class, and they could pull A's like low hanging apples from trees. Then they got to college and got destroyed, because they literally had zero idea how to study.
Honestly, one of the best lessons I ever got from high school was how to study. It helps that I'm naturally dumb, otherwise I probably would have skated until getting hammered in organic chem.