I didn't do any Open Days, so far as I recall you just applied and got interviews and went to them. I went to all of them by myself on the train including at least one overnight.
I then took a year out because my offer required it, except that when I got there it seemed no-one else had done so...
And my dad took me in the car, but we didn't know where the halls of residence was and when we finally found it they weren't expecting me because I hadn't replied to some letter or other, so I spent one night in a different room until they found an upstairs one (girls were always put upstairs) and didn't sleep because of all the screaming, shouting, music, running around banging doors etc.