I know of three verses that refer to Jesus at creation:
Here's John 1:1
In the beginning was the Word, and the Word was with God, and the Word was God.In chronological Bibles, John 1:1 is the first verse listed. Here's John 1:10
He was in the world, and though the world was made through him, the world did not recognize him.1 Corinthians 8:6
Yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live.That's a reference to God and Jesus, from which all things came. Which aligns with the above verses and the following verses.
Colassians 1:15-16a
He is the image of the invisible God, the firstborn over all creation. For by him all things were created...Hebrews 1:1-2
In the past God spoke to our forefathers through the prophets at many times and in various ways, but in these last days he has spoken to us by his Son, whom he appointed heir of all things, and through whom he made the universe.The Bible tells us God created everything through Jesus, the Word.
I don't have time to get into the details but if you're looking for a source for this belief...