Thanks for your question.
Repentance is absolutely necessary for sin to be forgiven. It is no good seeking forgiveness with no intention of changing the behaviour that led to the sin in the first place. This is serious. See Psalm 66:18.
True repentance means "to have a change of mind", that is of understanding.
When we ask, "A change of mind about what?" It is a change of mind about ourselves,
an understanding of our failure to live up to the standard God designed for us. In short, we are sinners. Once we understand that, then follows the command: "Be converted", a term which basically means "to turn round and go in the opposite direction". This is the practical result of true repentance. It is a realization that we need to redirect our lives, and to live more in harmony with the will of God and the commands of Christ
Repentance and baptism go hand in hand.
I hope you have found this helpful.