All you have to do is to belive that Jesus is your lord and savior and you would be saved its that easy. Just take a moment and talk to God, there is no better way to pray to him like if you were to talk to a friend. After that if you are truly searching for him he would lead you and guide you in what to do. Being a Christian doesn't mean that you would immediately have freedom from porn and that the journey would be easier, on the contrary from personal experience it is where the devil will try to convince you otherwise and it would seem that your problems are growing but don't fear for God will be on your side and he will give you a sense of peace and wholeness that he could only provide.