Self-studying an econ course over the summer showed me that I have a knack for statistics and economics (and I am highly considering having these two subjects be my majors in college). Does anyone have any recommendations on how to take these two classes further than just school learning? (Programs, College classes, research projects)
A course in Data visualization would interest you - often they are just one credit or you can find courses online since you like self study. But sometimes you need regression analysis first.
Take math to the highest level available to you.
In college, you may find math up to multivariable calculus, linear algebra, and real analysis to be useful for the statistics and economics majors.
My daughter was an economics major and is working in the field. In addition to the previous responses, learning some programming languages is a great idea (python, R,). My daughter also did an REU one summer (during college, not before) in data and social sciences. She was two courses shy of a math double major.
Big data is a field that might interest you. I’d read Factfulness too. Might get you thinking about how numbers paint a picture of the world.