Has God led you to the place and to the person or people that He would have you tell the story of a God who saves His people? If not, I would encourage you to pray that He would guide you to this place.
And when the time comes to share the life giving message of Jesus Christ, please rest assured in the knowledge that He has equipped you to reach those who He has placed before you.
I approach my evangelistic efforts with the belief that God will place before me some who he is or will in the future be calling. Armed with this belief, I speak as though I were speaking to someone within whose heart and mind the Holy Spirit is at work. Perhaps that is not the case, but that is not for me to know.
I just watched a video (added below) that I believe is an excellent resource for a Christian engaging in evangelism, especially but not necessarily exclusively in a one-on-one situation.
Dr. Lawson delivers a sermon on Jesus and the Book of Revelation with conviction and force. It is well worth watching and I think it would be difficult for a believing person to not get a return on the time invested.
But beyond this, I also believe that this sermon is a story that, if adopted to one’s style, would serve as the foundation for an excellent gospel presentation. I’ll let you decide if that’s the case with you. But whether or not it is, I would still highly recommend this video for it’s truth. Here it is: