This will vary from student to student, and major to major. Some students come to college knowing their major – although many will end up changing their minds. Others want more time to adjust to college, and might need a semester or two before they’re ready to zero in on what they want to do.
Although you don’t have to have a major chosen when you arrive at college, it certainly can help with some majors – like Engineering, Business, or the Pre-Medical degree tracks. These majors, and some others, require specific sequences of courses and prerequisites that usually are difficult to catch up to if the major was not decided early-on. Other majors, including Sociology, English and History, might not have a long list of prerequisite courses that need to be completed in a specific sequence.
Usually, though, the sooner you figure out what you want to do, the better, so you can see what is required.