This sermon by the late Dr. Walter Martin is decades old but I think is still relevant today:
If you don’t know Jesus Christ as your Lord and Savior you can receive Him into your heart and He can deliver you from darkness and sin and have your name written in His Book of Life.
If you are sincere you can say this simple prayer to the Father (it doesn’t have to be word for word):
“God, I recognize that I have not lived my life for You up until now. I have been living for myself and that is wrong. Please forgive me of all of my sins just as I forgive others. I need You in my life; I want You in my life. I acknowledge the completed work of Your only begotten Son Jesus Christ in giving His life for me on the cross, I believe in my heart Jesus is Lord and was raised from the dead and I long to receive the forgiveness you have made freely available to me through this sacrifice. Come into my life now, Lord. Take up residence in my heart and be my king, my Lord, and my Savior. From this day forward, I will no longer be controlled by sin, or the desire to please myself, but I will follow You all the days of my life. Those days are in Your hands. I ask this in the Lord and GOD Jesus’ precious and holy name. Amen.”