I don't think you need to submit your half yearly report for any courses (or at least none that I know of).
Some courses have extra selection criteria, but most are just decided by your UAI, so all you have to do is put in your preferences and hope to receive an offer after the HSC is over. It should tell you in the UAC guide if there is any extra stuff you need to do for specific courses, and when it needs to be done by, and if not-just ask your careers advisor or someone like that.
The final date to put in your preferences isn't until like August or something (if memory serves me...), so I wouldn't be worrying too much about it now, although it certainly wouldn't hurt to get organised and look into exactly what you need to do.