This may be a bit different, because I did VCE French, but my best advice is to try and practice your oral component, possibly with a friend or other classmate. It's also good to list a few possible questions that they ask, e.g., What are some hobbies, do you have any siblings, what's your favourite subject, and what are your plans after school. Take these questions, and practice some answers. If you are able to, prepare long sentences with impressive and advanced terms and grammar. If you aren't at that level, or can't prepare a large amount; don't worry too much about it
In terms of Listening, many teachers would recommend listening to people speaking in Italian, such as on the news, on YouTube videos, movies, and even podcasts. If you are able to find a few practice listening modules in Italian for Unit 1/2 students, I'd recommend trying to find question sheets too, as they work very well.
The most important thing is to remember that this is the first SAC for VCE Unit 1 and 2. Most students have rusty, and undeveloped skills at this point. If you don't get a high mark, that's fine. You still have this year and next to do well on your grade. One bad grade, especially in a Unit 1/2 subject, isn't the worst thing that can happen. Over this year, and next year, you will improve greatly. Take all this advice onboard, it helped me and my friends improve over time.