I think this is such a wonderful question to ask! Please try to look at your college experience as an opportunity to experiment — not something you have control or know exactly what to. About 70 percent of freshmen change their major by the time they are juniors. Just begin with the idea that you want to do something you like. Take the courses and see if you still like it. I was a mediocre student in most areas until I found how much I enjoyed and wanted to learn more about psychology. I never thought I would want to go to school and get a PhD, but it was interesting, I loved the material, and I was good at it. I liked creative writing, but also never thought about making a living as a writer. I certainly never thought I would want to get an MFA in writing after a PhD. If someone told me as a freshman I would ultimately have a career as a psychologist and a writer I would never have believed him or her. As a freshman the thing I thought I wanted to do most was become a physical education instructor. By the way, my parents had some other plans for me to become a plumber, if you would care to read about how well that went you can check it out here.
I offer my personal story only because I know it is not unique. If you ask 10 people how they ended up in their careers you would find that the majority ended up doing something different than they originally thought. The idea is to start out doing what you believe will let you thrive and take it from there.
There is good research to show that we regularly change our careers throughout life, or enhance them, or reconfigure the way we do them. Think of college as training you how to learn rather than just one thing you will do forever.
I would strongly encourage you to learn about your strengths. Dr. Ryan Niemiec is the columnist here on Psych Central for signature strengths. Check out his blog and take the survey to notice your strengths. This can be a great way to learn what you like to do, and how to flourish.