Brother, read
Isaiah 9:6. The Son who is to be given is to be known as both the Mighty God and the Everlasting Father. The apostles believed in one God whom they called Father, who according to Jesus is a Spirit. Those apostles also believed and taught that the man, Jesus Christ, is also somehow the manifestation in flesh of the God whom they believed in. Oneness is a modern term for believing Jesus is both the One and only God and yet also the human manifestation or "incarnation" of that God. Both man... and God.
As Martin Luther once said "in heaven the only God you will ever see is Jesus Christ".
In tthehuman Son of God we perceive the heavenly Father and God of all creation. And He sends his Holy Ghost into our hearts who is none other than Christ dwelling in us.
Trinitarianism and binitarianism and unfortunately even some versions of "oneness" I've heard are just intellectual attempts to explain God in the language of Hellenic philosophy and metaphysics. ie the "wisdom of the world" by which man FAILED TO KNOW GOD.