How to interpret the hexagrams in the Book of Changes, and what about heavenly stems and earthly branches? Please recommend a book.

If you really want to interpret divination, you can't learn it in a short time. I suggest you learn some basic knowledge first, such as reading the Book of Changes first, then reading your Book of Changes, and then reading the addition and subtraction of the Book of Changes and authentic divination. In short, if you just think about the Book of Changes to calculate divination, I think it is very difficult for you to learn, because there are many things, so you should read slowly!