I can understand why the various churches and denominations might confuse you—but you need to understand one important truth: In spite of their minor differences, all Christians center their faith in Jesus Christ.
This is why I urge you to turn first to the Bible (and specifically the Gospels of the New Testament) to learn about Christianity. The reason is because the four Gospels tell us about Jesus—who He was, what He did, and why He is important. To put it another way, the Bible is the source of our knowledge about Jesus, and you can't really understand what Christians believe (and why they believe it) apart from the Bible.
What does the Bible tell us about Jesus? It tells us first of all that He was born slightly more than 2,000 years ago, and He went about Palestine—His homeland—teaching people about God and demonstrating God's love by performing miracles. It also tells us that He was put to death because the authorities feared Him—but on the third day after His death He rose from the dead and later ascended into Heaven. And someday, the Bible says, He will come again to establish God's rule over all the earth.
How could He do all this? For one reason: He was God in human flesh. The Bible says, "For God was pleased to have all his fullness dwell in him" (Colossians 1:19). Ask God to help you understand who Jesus is—and then commit your life to Him.