First you need to know that God loves you: "For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have ever lasting life. For God sent not his Son into the world to condem the world but that the world through him might be saved." John 3:16-17

Note: "Whosoever" means you; put your name there. God loves everyone, no matter what you have or have not done.

The Bible says: "But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us."
Romans 5:8

Note: God sent Jesus Christ to die for us because He loved us, not for any other reason. Even before we knew God, He loved us.

Second we need to realize we are not perfect and we need help to get to God. The Bible tells us: "For all have sinned, and come short of the glory of God; Being justified freely by his grace through the redemption that is in Christ Jesus:"
Romans 3:23-24

Note: Help is in Jesus Christ, only through Him can we be made good enough to enter into everlasting life with God.

Third you have to confess Jesus, and believe in Him. The Bible tells us: "That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thin 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

Note: It is not enough to know about Jesus; you have to know Him personally. You do that by confessing Him as Lord and believing that He is the only way to God, and you will be saved. You come to Jesus just as you are, and then you let Him began to change your life as you choose to walk with Him day by day.
 

Prayer to ask Jesus to Save you  (example)
 

Dear Jesus, I know that I am a sinner and I need you. I believe you died on the cross for me and that you rose from the dead and are alive today. I want to turn from my sins (errors) and make you Lord of my life. Dear Jesus, please come into my life and heart now, and be my Lord and Savior. Thank you so much, in Jesus' name I pray. Amen
 

How can I be sure Jesus came into my life?
 

The Bible tells us:

"For whosoever shall call upon the name of the Lord shall be saved."
Romans 10:13

"I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture."
John 10:9

"But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name." John 1:12

We have all these promises from God Himself that assures us, if we will ask Jesus to come into our lives, He will. God never lies. Through His word (The Holy Bible), we can be sure of salvation.