Juniors are encouraged to either apply (or have a teacher refer them) to the QuestBridge Scholars Program if they are eligible. The eligibility requirements include that you are high achieving (in the top 10% of your class), have earned primarily A's in challenging courses, a strong writer, and have received recommendations from teachers. Read more details on their website.
The scholarship is generally designed for students who come from households earning less than $65,000 a year for a typical family of four, as the aim is enable students who don't have financial opportunity but do have the academic skills and ambition to attend schools that match them. The scholarship is for a full four years. Their site opens up in February (some of it is still about the 2020 application period, so make sure you don't get discouraged if it says it's closed).
Let me know if you have questions, or of course, visit the counselor's office.