You cannot train people to be evangelists. Either they are or they are not. If they are you won't stop them. If they are not, they will be as miserable as sin if they are made to do it.
My ministry is teaching which I received through four different prophecies from four different men in four different meetings. After that I didn't need convincing. I leave the evangelism to the evangelists and do not try to move in on their territory.
Of course you can train people to be evangelists. I'm not talking about a program or a method. Or a professional touring evangelist! I'm talking about giving some basic scriptural foundations to share the gospel!
1. What is the gospel? How can anyone share that gospel? Train them to really know & understand the gospel themselves
I took evangelism in seminary, from a former missionary in Hungary. We learned many ways of sharing the gospel. Giving our testimony of how God saves us is a good start! Know The Roman road, and don't forget repentance is an important part of seeing if people know the whole gospel, or just the good parts.
2. I agree your average person is not on fire to share the truth of Jesus. Maybe they will never be called upon to share their knowledge of Jesus to 100s of thousands of people. But everyone can share with their neighbour, or a friend or family member who are suffering.
3. Learn to recognize openings to share the gospel. So, if someone reflects on a fear of dying, or an emotional issue, any Christian should have the knowledge to spontaneously share the Plan of Salvation. I had been saved over 25 years when I took evangelism in seminary. I finally got a clear idea of how to simply explain the gospel, and lead people to Christ.
4. The Power of Prayer! Be on your knees. Pray for doors to open to share, pray for specific people to come to Christ, pray for the workers in the harvest, who really are gifted & called!
5. Urge people to understand the hour is urgent, and the need is greet! If a person isn't on fire for God, why would they be motivated to share the gospel? Stir up the Holy Spirit within.
As I said in my last post, everyone can share the gospel with a friend, a neighbour, or when God opens a door. We need to be prepared as to how to share, how to rely on the work of the Holy Spirit, and not our own works!