I ching and fortune telling, how to transition in the middle, which book do you need to learn?

If you want to learn fortune telling, you can buy a book written by a master of Yi Studies, which is mainly an introduction. For example, Li Shunxiang's The Mystery of Four Pillars is very good and suitable for beginners.

Then look at the ancient books on numerology, such as Sansheng Zonghui, Ziping Zhenxie, and Heavenly Descending the Pith. After reading ancient books, you can really master the knowledge of numerology.