First, you must acknowledge that you're a sinner. Admit to God that you know you have broken His laws, violated His commandments, and are deserving of His judgment.
"For all have sinned and come short of the glory of God." (Romans 3:23)
"For there is not a just man upon the earth that doeth good and sinneth not." (Ecclesiastes 7:2)
Second, you must repent. When the Bible talks about repentance it primarily means "to have a change of mind." Thus, to repent means that you are very serious about this. You are changing your mind. You have had a change of heart. You are doing an "about face" in your life. By repenting you are not saying you will become this "perfect person" overnight. You are simply saying that - from this day forward - it is genuinely your heart's desire to leave behind your life of sin and to begin following God and His will for your life.
"Unless you repent you will all likewise perish." (Luke 13:3)
"Repent and believe the gospel." (Mark 1:15)
Third, as just stated in the verse above, you must believe the gospel. The word "gospel" is used often in the Bible and simply means "good news." The good news is that God loves you immensely and gave his Son Jesus Christ to die and suffer God's wrath for your sin in your place. Jesus was God come in human form. He had no earthly father like you and me. Do not overlook this. This is one of many things that distinguishes Christianity from all other man-made religions. It's what we celebrate at Christmas Christ our Emmanuel, meaning "God with us." This is the true meaning of Christmas. Jesus Christ lived a perfect life, having never sinned. He also, of His own power, arose from the grave and conquered death. He's the only one to have ever done that. This is what we celebrate at Easter. When you put your faith in Jesus Christ - as your God-given substitute - all that Christ has accomplished is applied to your life as well. This means that God the Father now sees you as though you are perfect and sinless, and you too will one day conquer death and live eternally with God in heaven.
"He (God) made Him (Jesus) who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him." (2 Corinthians 5:21)
"For God so loved the world that He gave his only begotten Son, that whosoever believeth in Him should not perish, but have everlasting life." (John 3:16)
"Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me." (John 14:6)
Fourth, just call out to the Lord. Talk humbly and personally with God. He will hear you. Tell Him you know you're a hopeless sinner. Tell Him you know you deserve His judgment, but you desire to repent - to completely change the course of your life. Tell Him you believe the good news that He gave His Son Jesus Christ to die in your place. Ask God to save you. Put your faith in Christ, the one who bore all of God's judgment for your sin in your place.
"If thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation." (Romans 10:9,10)
"For whosoever shall call upon the name of the Lord shall be saved." (Romans 10:13)
Unbelievers often make fun of Christians when they talk about having been "saved." The word "saved," however, is a word used often in the Bible. You might ask "saved from what?" The Bible primarily means two things when it talks about our "being saved." The main idea behind the word is the concept of deliverence. 1) It means we have been delivered from the dominating and controlling power of sin in this present life, and 2) It means we have been delivered from God's judgment for our sin when this life is over. A person who has been "saved" is a person who has experienced what the Bible calls being "born again." (Read the gospel of John chapter 3 in your Bible.) This person now has new life in Christ. He or she has been supernaturally born in to the family of God and now belongs to God in a unique way that has never been true previously.
If these thoughts above have spoken to your heart and you personally have called out to the Lord and asked Him to save you, would you let me know that so I can rejoice with you? Or maybe you are definitely interested in what you have read here, but still have questions and would like to know more. That's perfectly understandable. It's wise to make sure you clearly understand what the Bible teaches regarding these matters. But don't delay! Keep pursuing God and His truth until you know Him personally through Jesus Christ His Son - until you have truly been born again! "You will seek me and find me when you search for me with all your heart." (Jeremiah 29:13)
If you would like, feel free to email me at firstname.lastname@example.org. I will gladly respond to you as soon as possible.