Open day's a fantastic idea, it'll get prospective students ready for the never-ending and fairly disruptive stream of construction that'll inevitably be around the entirety of their degree. I mean, it's been a week and I still haven't found a convenient way of getting to HAL from Medicine -_-
Year 12s, this shouldn't need saying but take everything that Faculty reps are handing out. If you're planning on doing a degree like Science with multitudes of options, any pamphlets about majors/minors etc. are going to be really useful in helping decide what path(s) you go down. A year ago I would have noped my way out of here if anyone suggested doing a developmental biology major, but late last year I found a brochure detailing the major and realised it aligned exactly with my interests.
tl;dr Bring a big bag for all your shit!