To study physics effectively, especially with a focus on astrophysics or quantum physics, it's essential to start with a solid foundation in mathematics and physics. A good starting point is to refresh knowledge at the GCSE level, as this provides the necessary basics. Following that, progressing to A-level mathematics will be beneficial, particularly in areas relevant to physics. Online resources like Khan Academy and Exam Solutions are recommended for self-study. Once comfortable with the foundational concepts, aspiring learners can aim for more advanced texts, such as Andrew Liddle's "Introduction to Modern Cosmology," to deepen their understanding. Engaging with math problems is crucial, as it reinforces skills and aids in grasping complex physics concepts.