Perhaps I'm a bit biased but I think reading books from the literary canon list can help improve your vocabulary. By this, I'm talking about Jane Austen, the Bronte sisters and Charles Dickens (to name a few). This is because they're writing style is completely different to the way contemporary novels are written, so their use of syntax is different and even the meaning of words are different. It also helps you appreciate how the themes they address, and I think it's great practice for analysing. I'm not sure about the English syllabus in VCE but in the HSC English syllabus, there are a lot of texts that are literary canons (especially in Extension English).
I will give you a disclaimer that it might be a bit challenging at first (the first book that I read from the literary canon list was Bram Stoker's Dracula and Year 6 me was confused why the novel was significant). I would suggest reading something light, like Oscar Wilde's The Picture of Dorian Gray, Jane Austen's Persuasion or Thomas Hardy's Far From the Madding Crowd
