The first step is to realize that God wants your life to be better! He doesn't want you to be stuck in sin and failure any longer, but He wants to give you a new life and the reason is because He loves you.
This is why the most important step you can ever take is to turn to Christ and ask Him to come into your life. He will forgive your past, and He will help you become the person you should be. The Bible says, "If anyone is in Christ, he is a new creation; the old has gone, the new has come! All this is from God" (2 Corinthians 5:17-18). By a simple prayer of faith ask Christ to come into your life today and He will.
When you come to Christ something remarkable happens: God Himself comes to live within you by His Holy Spirit. You may not feel any different but you are different, because God now lives within you. And one reason He lives within you is to help you, by giving you the strength you need to live a pure life. The Bible says, "The Spirit helps us in our weakness" (Romans 8:26).
Commit your life to Christ today. Then ask Him to strengthen you spiritually by reading His Word, the Bible, and praying, and having fellowship with other believers. Then begin each day by committing it to God, asking Him to guide you and help you resist temptation. With God's help you can become a better person the person God wants you to be.