I don't think anyone has mentioned this, and not to confuse you, but you should know that generally speaking there are two different communions which call themselves the Orthodox Church: Eastern Orthodox, and Oriental Orthodox. So if you just go to any Orthodox church in your area, it might not be what you think it is. So just to keep it really simple here's the deal:
Eastern Orthodox: Greek, Russian, Serbian, Ukrainian, Romanian, Bulgarian, Antiochian, Finnish, Georgian, Orthodox Church in America, etc.
Oriental Orthodox: Coptic (Egyptian) Orthodox, Ethiopian/Eritrean Orthodox, Armenian Apostolic Church, Syriac Orthodox (Jacobites), etc. Am I missing any?
Anyway, these churches split 1500 years ago over some doctrinal issues, about 500 years before the Roman Catholics and the Eastern Orthodox split apart.
Again, I hope this isn't confusing as you're just looking into it. I'm just trying to be helpful in your search. Most of us on here are Eastern Orthodox, and the Eastern Orthodox Church is the larger communion of the two, with roughly 250 million to 300 million members. I don't know the rough numbers on the Oriental Orthodox.
May God guide your steps.