@HereWeGo2023 Welcome to the thread and congratulations!
DS wasn't told anything about which room/band etc until he arrived, but I did push him to email and explain he was 6ft 4 so low ceilings were an issue, and he ended up with an enormous room with double bed.
From memory, re social stuff once he had accepted his place, there were emails from the college and he went to a Cambridge freshers drinks in London about 10 days before they started, where he met a really lovely group who have become his 'core' group really. His college also has an Xcollege2023freshers Insta page so may be worth looking for one for your DC's college?
He didn't have a FB account before he went but said he definitely needed one because a lot of college stuff, and most of the clubs/rowing stuff is posted on there....