What @3puppies describes is an ideal, and it’s a very educational experience if it works.
But for some kids, it won’t work. They may need the parent to take more of a leading role because they’re overwhelmed with academic work and ECs or because part of their mind is resisting the idea of leaving home to go to college, so they avoid thinking about it as much as possible. In both cases, though, if you leave it up to the student (and therefore the student doesn’t meet deadlines and ends up at the local community college), the student will be bitterly disappointed.
The whole process can be very tricky.
One thing I think parents need to remember is that the student hasn’t done this before. In fact, the student’s previous experiences are likely to lead to misconceptions. All of the student’s previous transitions from one level of education to another (say, middle school to high school) have happened almost automatically, with almost no effort on the student’s or family’s part. Unless someone tells the student that the transition to college is different and explains all the ways in which it is different and the steps involved in the process, the student may not appreciate the differences until it’s too late. They aren’t born knowing this stuff.