Finally someone is interested in University of Sydney. I graduated from there 4 years ago.<br>
You'd better come at least two weeks before the enrolment day to organise you accommodation. There will be plenty of sharing accommodation info on the notice boards around the campus. Take a tour to get familiar with the campus, with all the facilities etc. <br>
You need to choose your subjects on enrolment day. However, you can change any subjects in the first two weeks after the semester starts. It will be noted on each course outline, or check with the administration office.<br>