Did the Trinity Exist Before Creation?
Do you want to know how impossible it is to answer that particular question? Read Ecclesiastes 3:11, which states that God "...has put eternity into man's mind, yet so that he cannot find out what God has done from the beginning to the end." IOW, there's no way any human being can know what God has done.
Additionally, since God is the Alpha and Omega, the beginning and the end, and there's no way we mere humans can ever comprehend him, then what he has created is beyond our human ability to comprehend. Revelation 1:8, 21:6, and 22:13.