I am currently doing HSC General 2 at the moment, dropped from 2 unit at the end of year 11 which I was failing anyway, before then I was in 5.3 mathematics course, etc etc. Have a sibling who got band 6 in it last year.
The new syllabus doesn't appear to have too much added onto it, so much of the content in the syllabus I have will be similar to yours. When the time comes to do trial papers cherry-pick your questions accordingly (it won't be as easy as 2u), I suggest to ask your teacher now, what year 12 topics for your syllabus overlap with the old ones. Be proactive now, and you can maximise the large amount of trial, mid year and HSC papers available on the internet for your consumption.
Then go ahead and do the papers. Try and do as many as you can, 7 for me is my target before trials. Ignore the textbook questions unless they are for homework - I don't know if your school uses New Century but those questions in the book are very simplistic in comparison to the ones you get in past papers (after dropping from 2u to general the papers I did was a serious wake-up call for me). Give them a check, if you got it wrong, retry the question, if you got it wrong again, look at the solution, and so on and so on.
For now, Preliminary shouldn't involve worrying about your HSC. It's well over a year away at this point. Unless you are going for early entry (which none of the higher tier unis even have), Preliminary is a year of learning, taking HSC-style tests, and most importantly, learning from your mistakes and improving on them. Good luck man, sorry for long post.
