CHANGE YOUR MIND
A look at Strong's NT Concordance for Greek word for repent (metanoea) shows it means "to change one's mind". This is a fundamental change of mind about God and/or Jesus.
It's a directional change, away from and toward-to and it happens during the time in which the Holy Spirit is convicting an unbeliever of sin.
As Jesus said:
“... the Helper will ... convict the world of sin ... of sin, because they do not believe in Me," John 16'7-11.
Every unbelieving adult has a mindset, a worldview. Repenting is an intentional change, away from looking at everything in one way toward-to looking at everything in a new way.
A prime example of a repentant person's change is wanting to do the will of the Lord. Saul's response was, “Lord, what do You want me to do?,” Acts 9'6.
This foundational act of repentance is done once only.