>>659288
Firstly, get acquainted with scripture and the writings of the Church Fathers.
I would start with the Gospels (John or Mark would be good jumping off points), followed by the New Testament Epistles, then read scripture at your discretion.
For the Fathers, there are so many, here's just a few: Ignatius of Antioch, Justin Martyr, John Chrysostom, Ambrose of Milan, Cyprian of Carthage, Alexander of Alexandria, Athanasius of Alexandria, Basil the Great, Hilary of Poitiers, Jerome, and Augustine of Hippo.
Also, give the canons of the Seven Ecumenical Councils a read, these are the foundational councils that affirmed the faith as passed from the Apostles.
As for denomination begome Orthodox, we'll cross that bridge when you get to it, anon. First, learn.