I would just take all the required courses you have to for the first couple years and see what comes up. There's a lot of stuff you have to take multiple of for it to be an option for a major or job and it's pretty easy to see if you want to keep taking courses in a particular subject. Maybe divide some of your thinking in "half" with math and science to one side and the arts to another or different sorts of arts to one side or different sciences, depending of whether you are an "art" person or a "science" person? For the first couple years, 15-20 courses it's just an extension of high school, what did you like there?