You need to find colleges that offer a film&media major, with film study and screen writing classes (often as part of a media major) as well as production workshops then work on films as part of your extra curricular activities.
Colleges as different as UIUC and Franklin&Marshall offer the above.
You need to find internships that involve any sort of film work, including right now in Korea (as an extra, a volunteer for a TV show, etc.) and practice shooting short videos - documentaries about your life, a series of serialized 3mn fiction pieces, skits, “genre”* shows with attempts at special effects …
Perhaps get a following on YouTube, or get them sent to youth film competitions…
I suppose you’ve seen Super8 and the Fabelmans. If not, check them out.
If you are in the 11th grade, graduating December 2025, you would apply starting August 1, 2025.
What’s your budget - how much can your parents afford to pay each year (without loans taken on your behalf)?
What’s your GPA? Have you taken the SAT?