We all can make excuses for the reason we don't share Jesus with others. I'm shy, I don't know what to say, I don't have enough Bible knowledge, I don't have anything special to offer.
Peter and John could have said the same things. They were uneducated. They were common. But they had one thing that compelled them to tell others about their faith. THEY HAD BEEN WITH JESUS.
Have you been with Jesus? That is all you need. Simply tell others about your experience with Him. How has He touched you, healed you, and changed you?
The only thing you need is the only thing they needed. You have this in common with Peter and John: You have been with Jesus.