Even I'm a poor farmer's son from a backwater, that doesn't mean I can't get decent education. There is nothing about Jesus' life before about the age of 30. How can we know he didn't go to some school or that he was taught in some religious sect? It is all possible. Maybe he learned Greek in a school, maybe on a market place. He could have learned Hebrew at a temple.
We can't know this, therefore it's irrelevant. (Worse than that, it's a logical fallacy
.) If there's any point to discussing the subject at all, we have to confine ourselves to arguing from the "facts" as reported in the Gospels. Otherwise, we just accept ILuvEire's argument that he was God, therefore he knew every language, end of story let's all go out and get a beer.
I don't know, but was he literate?
We do know that because Luke[*] tells us "And as was his custom, he went to the synagogue on the Sabbath day, and he stood up to read." This indicates literacy in Hebrew; whether he was literate in any other language is a separate question.
[*] A man who, if he actually lived at all, never met Jesus of Nazareth before he was crucified. But see above.