If you are hoping to finish college in two years with an associate degree, it is good to have a solid idea on your major before you start. That changes somewhat in a university setting since your freshman year is likely general courses that are easily transferable to count toward different majors. However, even in the university situation, different majors may require a more difficult science or math class, so having a general idea is recommended.
One thing you know for sure is that you will spend less money and start earning a living earlier if you graduate more quickly. One reason for the current trend of increasing student loan debt is that students are changing majors more frequently, resulting in more years in school. It can mean tens of thousands of dollars more in student loan debt for every extra year you spend in college. Not to mention the wages you will lose by delaying your start date.