Your question difficult to answer. Better to ask what is Orthodoxy. You know what is catolikism, that way avoid even trying to be in position my church is better compared to your church.
Orthodox church is church founded by Jesus Christ on his Holy Apostles and their successors, bishops, archbishops, metropolitans and patriarchs. Head of each church is bishop.
In each church are temples (parokial churches), men monasteries, female monasteries, and many lay persons. Clergy below bishop are white clergy for temples: married men. Clergy for monasteries called black clergy and not married and from which are chosen bishops. These can be priests or diakons. Diakons can be monks or white clergy. These are helpers of priests.
Person become orthodox by Holy Mysteries of Baptism, Annointing with Holy Myron and Holy Communication of Body and Blood of Our God Jesus Christ. These Mysteries are given to adults and to small infants.
Orthodox temples are place like heaven. There is an entry room, a room for lay persons and a place for celebrating Holy Mystery separated by Ikonostas - wall covered with ikons. Ikons are pictures of holy prophets, saints, Mother of God, Christ.
Orthodox year contains 12 great feasts - and many other
smaller feasts. But Feast of All Feasts is Holy Paskha (Easter). This is celebrated by Nikean Council rule only after Jewish Passover (therefore, we are now only in 2nd week Great Fast (Lent)). Other feasts: Birth of Jesus Christ, Transfiguration of Lord Jesus Christ, Dormition of Mother of God, Birth of Mother of God.
There are many books for you to read about Orthodox church but pictures\ help: