How do I pursue my interests/passions without spreading myself too thin?

I am currently a soon-to-be sophomore in high school who is a little “disoriented”. I have a plethora of interests, which include entrepreneurship, medical research, robotics, law, government, and software engineering. As one of my endeavors, I know I want to attend an Ivy League college. More specifically, Harvard (I have the grades too). I have done my research on how to get through high school and construct a powerful resume to get into such college. Almost every bit of advice includes utilizing my said “passion” to apply myself to one or two. Currently, I am involved in a business club and a mathematics team at school, and I plan to get involved in Student Senate and Student Council sophomore year. Also, I want to either learn an instrument or learn how to code via taking an online computer science course. Since my school is fairly new with relatively little extracurricular opportunities other than sports, I plan on starting either the school newspaper, the debate club, or the science bowl that would compete at the National Science Bowl competition.

I indeed want to pursue my passions because I am interested in them, not just because I want to get into Harvard.

I have read that it is not good to “spread myself thin,” meaning that I join/make a club for each interest. I have read that school admissions see this as a person who is well-rounded: mediocre at everything, master of none. So, how can I discover my true passions without spreading myself thin and looking/being mediocre in everything extracurricular I do?