They have always been co-equal and there always has been rank; not that one is more important than the other; but rank as in functionality and in position and order--not importance or equality.
What did Stephen see (which gives us a picture of what is the present):
Acts 7:55-56 But he, being full of the Holy Ghost, looked up stedfastly into heaven, and saw the glory of God, and Jesus standing on the right hand of God,
56 And said, Behold, I see the heavens opened, and the Son of man standing on the right hand of God.
Jesus sits on the right hand of God. I believe he stood on this occasion as a special welcome to Stephen the first martyr of the Christian faith. There is much about the trinity that we don't understand. I don't ask you to try and understand it all. I just ask you to accept some very basic facts that are presented over and over again throughout Scripture: that there are three persons in one God: God the Father, God the Son, and God the Holy Spirit (in that order), and that these three are one. They are co-equal, co-existent, and co-eternal, having different functions and purposes, and yet are three distinct persons, but at the same time being one God. I could give you a much more detailed definition but this is a simple one.
God the Father is first. God the Son in His glorified body sits at His right hand. And then their remains God the Spirit. We don't understand. We will understand more when we get to heaven. There are some things we will never understand but must accept by faith. The trinity helps to define God and differentiate him from other false religions.