Question: Who created God and who created the creator of God if God was created?
This question reminds me about the question: “How tall is a Chinese person?” If I don’t know which Chinese person we are talking about I can’t say the answer.
So in your case are you asking about the God who is created by people, as the atheists say? Or do you think God is so complex, that it is impossible that he exists? Or do you mean the God in which the Jews and Christians believe? If you refer to the latter, I can answer the question to some extent. There was no creator of God, He is the creator of heaven and earth, animals and humans.
God has no beginning
In your question there is the premise that God must have a beginning because everything has a beginning. In that case, whatever my answer may be, you will ask what came before. We as humans think in time, as we experience the sun. Our thinking in terms of 24 hours a day is related to one turn of the earth. But if we are not under the influence of the sun, there is no time. Time implies a beginning and an end. Without time, there is no beginning, nor an end. It is like a circle: it has no beginning and no end. God created the sun, by doing so He created time. God is immortal, He had no beginning, He is now, He has no end. Hard to understand for us mortals.
The question about the creation of God has a long history. In the sixth century the people in church made the Athanasian Creed. In this confession of the faith there is a passage about this topic. It says: “…The Father uncreated; the Son uncreated; and the Holy Ghost uncreated. The Father unlimited; the Son unlimited; and the Holy Ghost unlimited. The Father eternal; the Son eternal; and the Holy Ghost eternal. And yet they are not three eternals; but one eternal…” A complete mystery, yet part of the Christian creed.
If you want to read more about this topic, please read the book “Who made God? – Searching for a Theory of Everything”, written by professor Edgar Andrews in 2010. You may visit his website: http://whomadegod.org.