Nothing stopping you from going to NYC, staying in a hotel and wandering around the campus. You can’t get into most buildings without an ID or a student to usher you in. The latter shouldn’t be too hard to find.
You’re not going to be able to find a roommate. First, they assign you one, unless you get a single room in John Jay. Second, all your potential roommates/future students will still be at home. You may have a local alumni club which holds a reception for admitted students (if coronavirus doesn’t cancel those too).
Choosing Columbia over a comparable school is simple: Do you love NYC and are you dying to live there? Are you independent and self-reliant? if so, yes. If not, go somewhere else.