My advice for the best preparation in Maths will be the same for any high school student, regardless of what year of education they are in. That is, to make sure students engage with the theory (formulae and concepts) in lots of different ways (in class, through the textbook, YouTube videos, hands on work and through Project Academy!) to make sure you understand them in the best way possible, rather than simply memorise them. Understanding how to derive formulae rather than simply memorising them will help you understand how they work, it will help you spark an appreciation for Maths and also give you a better platform for doing harder questions. Then, because Maths is a very skills-based subject, it is essential to apply that theory by practising lots of questions, using both the textbook and past papers. Students should start with the 'easier' questions in the textbook (generally the first few questions in each exercise) and work your way up. Make sure to check your answer after every question to detect any issues in your working out early on, rather than let them become habits. A good strategy is to work through past papers and write down the things you don't understand, then use textbook questions to drill those weak areas.
Make sure to collect past papers early and work on them throughout the year, avoid cramming them just before exams. You will learn much better by doing past papers consistently, so schedule them into your week!

The first thing to remember is that the main goal of Maths Advanced is to challenge you with some higher-level concepts (compared to Maths Standard), such as differentiation and integration. This is best for students who think they have a good grasp of contents so far and would like to challenge themselves some more. I personally enjoyed these topics a lot, and I know that they have very important applications in subjects like Engineering and Physics in Uni. If you're finding the pace of Maths so far okay, would be happy to challenge yourself some more and are interested in those Uni degrees, definitely give Maths Advanced a go! The difficulty of Maths Advanced is something that is subjective, but remember that all Maths courses are supposed to be difficult in some way to challenge you and push you to work hard. You wouldn't learn anything if they were all easy!Additionally, Maths Advanced is a prerequisite for a range of university degrees (especially at the University of Sydney). Make sure to study the prerequisites of your degree well, to avoid having to do extra study after year 12 to catch up (through 'Bridging' courses).

Year 12 Maths builds on the concepts learnt in Year 11 Maths. For example, in Maths Advanced students learn about trigonometric functions and identities, as well as what logarithmic and exponentials functions are and how to work with them (along with other topics). Students also do an introduction to what differentiation is, then bring these concepts together to differentiate trigs, logs and expos and apply them to real world scenarios! Along with other similar topics, this makes the heavy focus on calculus in Year 12 Maths the fundamental difference from Year 11 Maths. Year 12 Maths is of course more difficult than Year 11 Maths, but a good work ethic and study plan throughout Year 11 will make Year 12 much easier to go through.