To prepare for the International Physics Olympiad (IPhO), a solid foundation in physics is essential, which can be built through coursework and self-study. Basic calculus knowledge, including derivatives and integration, is beneficial for understanding physics concepts. Recommended resources include Serway's physics textbook and the Feynman Lectures, both of which are praised for their clarity and depth. Enrolling in a physics class is also advised, as it provides access to guidance and support for any questions that may arise during study. Continuing to strengthen calculus skills alongside physics learning is crucial for success.