“Whom shall I send? and who will go for us?” Then said I, “Here am I, Lord. Send me.” (Isaiah 6)
You say the Lord has called you into His work. You’re still young and you’re excited, although with a proper amount of fear and uncertainty on what all this means.
You’re normal. Been there, felt that.
We might have cause to worry if the living God touched your life and redirected it into His service and you picked yourself up and went on as though nothing had happened. Amos said, “I was gathering sycamore fruit, and the Lord God called me.” He said, “The lion roars and you will fear. God calls and you will prophesy.”
The call of God is almost as life-changing as the original salvation experience itself.
So, give thanks. And give this a lot of prayerful thought.