One of the cool things about law is that specializations tend to be developed as you work. This buys you some time to think about what kind of law you want to practice.
While I haven't heard of any "majors" in law school. Most schools do offer concentration programs if you want to do a particular type of law (IP, litigation, environmental, whatever). These might affect your choice of school if you're already interested in a particular area, but if you're not, it's probably not a problem. Regardless of where you go, the first year will be the same. So you definitly have some time to think about what type of law you like and get some exposure to different legal areas.