No, you don't have to wait to make your decision for Christ -- and I sincerely hope you won't. The important thing is not how you make your commitment, but that you actually do make it.
Let me explain it this way. Before we can respond to Jesus and become His followers, we must first understand with our minds who Jesus is and what He did by dying on the cross for us. He was God in human flesh, who came down from heaven to become the final and complete sacrifice for our sins. But then we must respond to Him with our wills -- actually deciding to commit our lives to Him and trust Him as our Lord and Savior.
And you can do this today -- right where you are -- by simply telling God you believe that Jesus died and rose again for your sins, and that you want to invite Him into your heart and become His follower. The Bible says, "If you confess with your mouth, 'Jesus is Lord,' and believe in your heart that God raised him from the dead, you will be saved" (Romans 10:9).
Then take your stand publicly for Jesus -- which He commands us to do. (This, incidentally, is one reason why I ask people to come forward publicly, openly confessing their faith in Jesus.) Jesus said, "Whoever acknowledges me before men, I will also acknowledge him before my Father in heaven" (Matthew 10:32). Seek out a church where Christ is preached, and where you can identify openly with God's people and grow in your commitment to Christ.