Was Jahwah First God Of The Jews? And Was He A Real Living Person?

I believe you mean Yahweh.  "I am that am".  And no, I have never heard that he was a person.  Yahweh was the first and only God of the Jewish nations.  He claimed them as His people, hence why Jews are known as "the Chosen People of God".
I am curious as to what literature you may be speaking of that refers to Yahweh as a human being.

Yeah, he's as real a Jesus was and he lives just round the corner from me. In fact I'm sure I had quite the drunken conversation with him the other night. Oh please!

I know you asked this a year ago, but I would like to answer you.  Yahweh is one of the names of God.  Yahweh was and is the God of the Jews. They have never had any other God, so he was not only the first but is still their God.  He is the same God that we Christians have - the one and only true GOD.   Jews and Christians have the same Adam, Moses, Noah, Abraham, etc., we even share  the same Old Testament.   Jewish people do not believe in Christ and / or the New testament.   And No God Himself was never a Human . He has " always been "  -However he sent his Son ,Christ to earth as a human.  Christ was both Deity and Human.          Hope that helps.