If you really want to properly get ahead then you can self learn - personally this worked really well for me, I just learnt all the content with the YouTube channel 'Mcgrathematics', did some of the chapter review questions in Cambridge after each topic and then got to dive into past papers very early in the year. Be warned though this does definitely take a fair bit of time and you do have to be willing to consistently revise with a past paper weekly ideally until the HSC to maintain the skills - but imo it does definitely reduce stress and increase results if you're aiming really high.
Other than that just try to do as many past HSC/trial questions as you can throughout the year rather than basic repetitive textbook questions and leading up to exams do as many past papers as you can because they are a very effective study method. ALso make sure you have a mistakes book, and write every single mistake you make it maths throughout the year in it - this forces you to consciously recognise every error you make and prevents them from occurring in the future.