Provided you are sincere in your desire to become a Christian, all you have to do is open your heart and pray that our Lord welcomes you into His arms as His. Repent of any misdeed of the past, and pray from the heart for forgiveness. Accept Jesus, as John 3:16 states: "“For God so loved the world, that He gave His only begotten Son, that whoever believes in Him shall not perish, but have eternal life." (NASB) Acknowledge you are a sinner, as we all are, and know in your heart that our Lord God hears us, He hears our prayers, and that there is nothing He can't do, in His time, according to His will.
Then be prepared to begin growing in your relationship with our Lord God. If you don't have a Bible of your own, you can read & study the Bible online. Biblegateway.com is an excellent source for the Bible, with the option to read/study from a variety of Bibles: King James, New American Standard Bible, etc. That site also has links to help with your study of Scripture.
Blessings, Mementomori ... and my prayers are with you!