tsch Hi there! Firstly, it sounds really cool that you want to start preparing for VCE. Are there specific subjects you want to take? My biggest tips currently are to just focus on your study techniques. Of course, year 9 is nothing like VCE, but any steps you make towards improving study habits and the way you learn is really beneficial. Whilst I never really thought much about VCE in year 9, I still started to make progress towards improving my study methods. This involved watching A LOT of study technique videos and doing a heap of trial and error (which you'll probably keep doing right into year 11 and 12). I also read books on study methods (haha I'm a bit of a study nerd) and improved the way I planned my time (aka starting making proper to-do lists and time blocking). If there are specific subjects you're interested in, you could try watching some videos or reading up on some of the topics that may be covered. You could also chat to your teachers as well to see if they can point you to any resources. You can also look into doing a subject early, but there's no pressure or need to do this (you don't need to do an extra subject to do well, and you'll regret doing it if you just do it for the sake of doing it).
However, please don't stress yourself out about VCE. You've got a long way ahead of you, and there's no need to push yourself too hard (this goes for during VCE too). Improving your study methods and habits is important, but you don't need to do any crazy preparation for VCE. I never really did and it didn't honestly matter. I just made small amounts of progress along the way and tried to learn from my mistakes. So don't stress too much about it. VCE is important, but it really isn't everything in the grand scheme of things.