Some day God may call you to be a preacher or missionary, and I hope you'll respond if He does. When I was young, I resisted becoming a preacher -- but God had other ideas, and it's been a great privilege to tell others about Jesus and invite them to give their lives to Him.
But most Christians aren't called to be preachers or missionaries. God has other plans for them, and they can be just as important in God's work as any preacher or missionary. Every day they meet people who do not know Christ, and may have nothing to do with a church. Who is better able to tell them about Christ than someone who knows them and sees them every day? Jesus said, "You are the light of the world" (Matthew 5:14).
Pray about your future, and ask God what He wants you to do with your life. Then trust Him to use you, no matter where He leads you. God knows all about you; He knows your abilities and interests, and He knows what's best for you. Put your future into His hands.
But ask God also to use you right now to point others to Christ and the new life He gives to all who follow. All around you are young people who are confused and headed down the wrong road. Ask God to use you to tell them about Jesus, who alone is "the way and the truth and the life" (John 14:6).