You must believe. You must believe in God and the truth of Scripture. You must believe that He loves you. You must believe that you have sinned and that your sin has separated you from God. You must believe that Jesus is the only way to get right.
Belief is essential.
It is the beginning. You must repent. To repent is more than just being sorry. It is that, but it is also turning away from the sin that you are sorry for. It is a turning away from sin and turning to God.