Before the creation of time, before the creation of matter, the Word was. You and I trace our history back to our parents, grandparents, or if we are lucky, we have records going back even before then. But the Word cannot do that. He does not have a beginning.
The Word took on flesh in time (John 1:14). We know he became a human being, was given a common name, and was born in Bethlehem. We can trace his history; we know about Mary and Joseph. There was a very definite beginning in time and history. But the conception and birth of Jesus Christ was not his beginning. We can say that there was a time before Jesus was born, a time when Jesus of Nazareth did not exist, a time before the Son took on flesh. But we cannot say that there was ever a time when the Son of God did not exist.
The Word has always been the eternal Son of God. He is outside of time, he existed before all things, there has never been a moment when he was not.
1 In the beginning was the Word, and the Word was with God, and the Word was God.