My 2 cents: 1. Get a job, learn the industry you are working in reasonably well, and only then open your own business in that field... otherwise you have no idea what you are doing. Or, 2. Go to college and then get a job and then #1.
My experience is that just getting into the "working world" helps to figure out what you want to do. Take any job you are reasonably comfortable with now, you're not married to it forever.
Also, the vast majority of people who like what they do didn't go straight into that field. It takes trial and error to see what you like, don't be afraid to move around, and don't despair if you don't know exactly what you want to do now.
Hatzlacha!