God created the world, including men, for the purpose of His glory. The first man, Adam, sinned which caused a separation between God and man. Because we descend from Adam, we have a sin nature that separates us from God that we cannot overcome on our own.
God sent His Law down through Moses, listing rules and regulations and animal sacrifices for sins in order to show that man cannot possibly be forgiven on their own terms.
God sent His Son, Jesus, God in the flesh, fully God, fully man, to live the perfect life we could not to be a sinless, perfect sacrifice for our sins, unlike the animals previously sacrificed. This sacrifice was once for all sufficient for those who believe.
If you recognize your sins and sinful nature, repent of it and confess Jesus as both Lord and Savior (both those terms are important), strive to follow Him and His teachings (i.e. the Bible), you will be saved.