If I were you, I'd be focusing on reading, watching, and playing as many texts as I can. Not just set texts - anything that you enjoy or wanted to read but never had the chance.
First of all, this will give you a good idea of supplementary texts. For example, if you go and play
The Last of Us and start thinking about discovery and concealment (both in physical landscapes and between characters), by the time you get to starting school you've already gotten a strong supplementary ready to go. And you've had a bloody good time "studying" it as well.
But more than that, it gives you a fun and interesting avenue to hone your analytical skills. In my holidays, I used to watch movies and read books asking myself "what's going on here? what's the author trying to do? Oh, that's an example of
tricolon - hah, I must be pretty smart to get that!" And that sort of casual analysis then helped hone my thought processes when it came to the drudgery of prescribed texts and areas of study.
The biggest piece of advice that I can give for better English results (which occurs in my new
online training platform for English and writing skills a lot) is: read widely, and read deeply. The more you read, the more concepts you'll be aware of and able to compare other things to. The deeper you read, the more acute your analytical skills will be. Plus you'll also find yourself writing with greater fluency and flair. When it comes to writing, reading = learning from the best, after all.
Hope that helps.
