Congratulations on making the greatest decision of your life. Here is what it means to follow Jesus Christ.
Responding to the invitation and repeating the sinners prayer means that you have confessed with your mouth and believed in your heart that Jesus Christ is Lord (Rom 10:9). The bible promises that all who call upon the Lord will be saved. That word "saved" and the word "salvation" coincide, you are now saved from your sin and eternal punishment through salvation.
The word salvation in greek is the word "sozo" which is translated healed, delivered, and made whole. Through the work of Jesus on the cross, and His resurrection you can now be healed, delivered, and made whole. You are forgiven of your sins, and you can also be healed from the sins committed against you.
In scripture Salvation and Baptism always go hand in hand. "Repent and be baptized". We encourage you to follow Christ in the waters of baptism, die to your old nature, and rise again with Christ. Also baptism is a public declaration of your faith. It is an important next step in your journey.
Before Jesus' ascension he promised his believers that they would receive "power" when the Holy Spirit would come to them (Acts 1:8). 50 days after that, the Holy Spirit revealed himself to 120 people. The evidence of the Holy Spirit is new life, new power, and new desires. The Holy Spirit convicts us of sin, and reveals to us the person of Jesus. Spiritual gifts also accompany the presence of the Holy Spirit, things like healing, faith, prophecy, discernment, speaking in tongues, and the interpretation of tongues (1 Cor 12).
In scripture there are instances when the Holy Spirit came upon people through the "laying on of hands" and prayer. We believe the gift of the Holy Spirit is for everyone.