I'm thankful you've asked Jesus Christ to come into your life; it's the most important decision you or anyone else will ever make -- both for your life right now, and for eternity.
And if you were sincere about your decision, I want to assure you that God has already forgiven you, and Jesus Christ has already come into your life by His Spirit. How do I know this? I know it because this is what He has promised to do -- and God does not lie! When we put our faith in Christ and sincerely ask Him to forgive us and come into our lives, He will do so. Jesus said, "All that the Father gives me will come to me, and whoever comes to me I will never drive away" (John 6:37).
Does this mean you'll never sin again? No, of course not. Yes, Christ now lives within you -- but so does your old sinful nature, and you'll still be tempted to sin. And when you do sin, your fellowship with God is hurt and you feel distant from Him. But your relationship doesn't change; you are still God's child. More than that, He wants to forgive you. The Bible says, "If anybody does sin, we have one who speaks to the Father in our defense -- Jesus Christ, the Righteous One" (1 John 2:1).
Now that you've given your life to Christ, make it your goal to grow stronger in your faith. Make the Bible and prayer part of your life every day, and draw strength from your fellowship with others in your church.