I'm currently a sophomore in high school with a GPA of 3.83. If my SAT or ACT is high, can I get in?

Columbia considers applicants holistically. While they look at GPA and SAT/ACT scores, they look at more than that. Work to keep your GPA high because the average at Columbia is about 3.7. The higher your GPA, the better your chances. For the SAT, the average (mean) score is 1530. Students with lower scores have been admitted, but you should aim for, at the absolute minimum, the mean score. In addition, you should take advanced classes - IB, AP, and/or honors courses. You may consider enrolling in a local community college to take a couple courses there, as well. I would also strongly encourage you toward volunteer service. It sets you apart.