Do I become an entrepreneur, cosmetic dermatologist or go into wall street? and how to get there

So I have so many passions. I’m very entrepreneurial and have started a successful social media company which has 2 million users and 1.2 million seed funding. I’m 16 and in Australian and in two years I want to study in the USA. This has been my dream for so long. I really want to go to Stanford but I’m not sure what to study. I want to be an entrepreneur, but I love fashion and wall street (banker, hedge funds, day trader - big bucks and I get so inspired when I watch wall street, I love everything about it!) but then again a stable job is cosmetic dermatology and I’m really really interested in that.

Please help me decide what I should do. Can I have options? Can I study my undergrad and grad in the US if I want to become a cosmetic dermatologist? And what does a dermatologist usually study for the bachelors degree? Is it possible to still major in Economics BA and then specialise? That way I have options?

And are there any prequisities for Stanford to become a dermatologist - or doesn’t it matter what I want to be until I get a masters, phd ect?