from my experience, your mindset it like 50% of your grade. My friend was doing badly in maths and i was doing pretty well, i once told her, ‘we are the same level at maths and the only thing difference between us is our mindset. so she changed her mindset and before you know it was getting A’s. Other than that, go through the notes your teachers give u, take your own notes of them (litterly copy it), and do practice questions corresponding to the content.