I don’t remember the timing, but we took my oldest daughter on a campus visit early in the process just to understand what it was all about. Parents had been out of school for decades and we were sure things had changed. So we traveled about an hour to a nearby school for the experience. It wasn’t anywhere we considered attending, but we took a lot out of the experience - knowing what to expect, what questions to ask, and how to get the most out of the experience.
Looking back. It was better to figure this out in advance rather than after the first visits that actually mattered.
My younger daughter also took a lot from visits with her older sister, a few years before she was looking.
If you have 1/2 day to spare on the trip, I think it’s worth the time investment - just pick a school. If nothing else, the Harvard visit/tour was historically interesting, and MIT has a very good presentation.