The I Ching, or "Book of Changes" is a very very old (3000 year or so) Chinese text. Without going too far into the finer points of Chinese philosophy, it is both Confucian and Taoist, and a little background knowledge of Taoism (two opposing elements constantly transforming into each other) will help when reading and interpreting it. It is an oracle, a divination device, something to look to for spiritual guidance and insight into your fate. It has 64 chapters, called hexagrams because each is made up of six lines, either broken (yin) or unbroken (yang.) Beyond it's long and deep influence in the East, folk in the West have found interesting uses for it, from inspiring early computational theory (see Leibnitz) to avant-guarde whosiewhatsits (see John Cage.)
To use the I Ching as an oracle, you start by asking a question. Usually the question is phrased "what of..." and should be something that is emotionally significant, that you are already reflecting upon but seek additional guidance, something specific, and not something with an either/or answer. You meditate on this question, flip a coin 18 times (there is also a stick method), and finally follow a little order of operations to get your hexagram(sometimes 2 hexagrams, which I will explain later) to guide you in your question. Interpreting the hexagrams is difficult. You start have the core name of your hexagram, the names of the two trigrams that compose it, then the image, then the decision, then the commentary on the decision, then commentary on the image, then modern interpretations and descriptions of these two commentaries, then commentary of transforming lines (more on this later), then maybe your second hexagram. In all this, you need to do a bit of Taoist interpretation (thinking of how opposites flow into each other), Confucian interpretation (thinking of duty and harmony with heaven's mandates), and how the hexagram interacts with its neighbors and location in the overall text. The metaphors are ancient, mystical, and have a certain Chinese grammar that I struggle with. There are also irksome discrepancies between different translations. The one most known in the West is the Wilhelm translation, but I really like the Huang, and that's the one we'll be using (a link is below.) Despite all of this struggle in making sense of just what under heaven this book is saying, something sings in there. And I'm always happy to introduce people to this song.
And I found a fun way of making this introduction by adapting it to Calvinball Variations. This game is a standalone set.
You ask your question, then go to the Ravine area of the park (starting from Center Drive about 200 meters before it hit East Drive) which is Brooklyn's only forest and a woodland of forking paths. You start running (or walking) and each time you hit one of those forks, you flip your coin and go left for heads and right for tails. Mark your answer, run and continue to meditate and reflect on your question (or perhaps clear your conscious mind of the question and let your legs do the thinking) to the next intersection, then flip again. You do a total of 18 runs and flips, then follow the little order of operations. The word document below has these operations described in a worksheet, and is as clear and concise as I can make it. It's not super complicated but is a bit odd and is easy to mess up. Then you get your hexagram (or two) and some guidance from the whatever high atop the thing concerning whatever it was that you were unsure or perplexed about.
Here is a pdf the the hexagrams from Alfred Huang's translation. More commonly encountered in America is the Wilhelm translation, but I like Huang more. https://www.labirintoermetico.com/09IChing/Huang_A_The_complete_I_Ching.pdf