High school sophomore interested in economics

All,

I am currently a high school student who plans to pursue a degree in economics. I am seeking advice on how to develop myself in this field and create an appealing application to colleges. My dream schools include: UChicago (for their econ program), Princeton, Brown, Pomona, CMC, Harvey Mudd, Northwestern, and Vanderbilt. I am entering sophomore year, and my GPA is currently a 3.92 (UW). I play the piano (multiple state awards), participate in the school newspaper (I am an news editor), and I am also the president of a history olympiad club, and we have participated in some state competitions. Besides this, however, my ECs are very weak (and generic), and none really describe a specific passion. I plan to join the Model UN team this coming year as well as Speech and Debate. Does anyone have tips on how to develop myself in this field? Are there any oppurtunities (summer camps, programs, projects) one might recommend?

Thank you for reading.