If you are studying IG physics or doing a 2 or 3 year MYP course, you are in Year 9 (Grade 8) or above, here is the page where you can download the Cambridge syllabus or everything you might need to know to pass exams. Download the file for your entry year and look for the Contents part, containing Core and Extended. Core is for grades U to C, extended from D to A*. Remember, they’ll ask you questions in different contexts, same stuff, just dressed up differently.
This is a very useful site. All the past papers you need, (CIE is the International one)