Sacred Jewish Practices?

Answer 1

You would be refering to ; Kabbalah (Hebrew: קַבָּלָה‎, Tiberian: qabːɔˈlɔh, Qabbālāh, Israeli: Kabala) literally means "receiving", in the sense of a "received tradition", and is sometimes transliterated as Cabala, Kabbala, Qabalah, or other permutations. Kabbalah esoterically interprets the Hebrew Bible (Tanakh) and classical Jewish texts (halakha and aggadah) and practices (mitzvot), as expressing a mystical doctrine concerning God's simultaneous immanence and transcendence, an attempted resolution to the ancient paradox of how the ultimate Being—"that which is not conceivable by thinking" (Isaac the Blind)—nevertheless comes to be known and experienced by the created world.

Because of the interpretive liberties taken by kabbalistic thinkers, and the possible heresies to which they may easily lead, study of Kabbalah was traditionally restricted to a select few Rabbis and Torah scholars. As Joseph Albo puts it in his Sefer Ha-Ikkarim (II:28, 15th century, trans:Husik), "This is why the science treating these things is called Kabbalah (lit. tradition), because tradition must be followed in the study and the practice of it, else one is liable to commit an error and to worship as God some one other than the Lord."

Answer 2

You need to be more specific in your question if you want a good answer.
Also be aware that many people do'nt like to talk about sacred practices to outsiders, so be respectful as well as specific.