I am aware the Church is against fortune-telling and astrology, but isn’t the I Ching all right? I mean, it’s a Taoist holy book.
It is not a problem to study other religions, as a matter of fact so many Catholic Apologists and theologians would almost HAVE TO do this. But there must be a think line drawn between simple study and practice. The Church isn’t against reading any book to know about any religion, but is against practicing or believing in things contrary to the traditional teachings of the Church as revealed by Christ and handed down through the Apostles.
The Catechism of the Catholic Church says:
All forms of divination are to be rejected: recourse to Satan or demons, conjuring up the dead, or other practices falsely supposed to ‘unveil’ the future. Consulting horoscopes, astrology, palm reading, interpretation of omens and lots, the phenomena of clairvoyance, and recourse to mediums ["channelers"] all conceal a desire for power over time, history, and, in the last analysis, other human beings, as well as a wish to conciliate hidden powers. They contradict the honor, respect, and loving fear that we owe to God alone. (CCC 2116)
I usually advise anyone without sound theological background not to embark on such study since the many questions that new discoveries can bring up might lead you into a different, wrong path if you do not have the right answers already. So i advise you consult with your spiritual director (and you should have one) to help you examine your motives for studying I Ching, and if it is pure, you can, with the blessings of the director and his guidance go into such research.