Hey!
I am a junior in high school currently.
My sophom*ore year was really rough and due to covid and the hospitalization of my mom, as well as a lack of general motivation, I finished my sophom*ore year with a couple of C's.
In my experience, as long as you demonstrate an upward grade trend (your grades improve throughout high school), you will be absolutely fine. One C in your transcript will not greatly impact your GPA and if it is a rare occurrence some colleges will just consider it a fluke.