Answer:

And the LORD God said, “It is not good that man should be alone; I will make him a helper comparable to him” (Genesis 2:18).

Ephesians 5:22–25

1 Corinthians 11:3

Okay. First of all, this person wasn’t exactly a boy. Adam was a man. And we know that, as our infinite Creator, God can do whatever He wants to do. When He made Adam first, God was teaching us how He wanted our families to be. He made Adam to be the head of the family. See in our Bible verse? It says that God wanted to create a “helper” for Adam, so He created Eve. Eve was the perfect complement to Adam. 

Adam was the leader of that very first family. Adam was not better or more valuable than Eve. It was just that God knew someone had to be the leader, so He made that leader Adam. By doing this, God showed us that He wants the husband, the dad in the family, to be the spiritual leader in the family.

Source: https://answersingenesis.org/kids/god/why-was-the-first-person-a-boy/