A thirteen-year-old interested in math and physics seeks recommendations for self-study books from trigonometry to physics. Suggested resources include "Introduction to Geometry" by Rusczyk, "Trigonometry" by Gelfand, and "Precalculus" by Rusczyk, which are noted for their suitability for self-learners despite their difficulty. While some recommend Euclid's "Elements," it is considered challenging for self-learners, and alternatives like online courses from The Art of Problem Solving are also mentioned. Overall, the consensus is that the recommended books can be sufficient for learning without the need for additional courses. The discussion emphasizes pacing oneself and utilizing supplementary resources for better understanding.