Open your Bible, turn to Genesis 1:1, and start reading. I’m not being facetious—if you’re not familiar with the Bible, then you need to familiarize yourself with it. There are arguments to perhaps start in the Gospels and then go to the Epistles, but then you need to do some work with the Old Testament.
There are many study Bibles available, like the Reformation Study Bible. Study Bibles are excellent. As you’re reading and asking questions, they contain helpful footnotes that are not too long or too distracting, and they help you understand the flow of the Bible.
You also need to go to a Bible study. You need to go to church. You need to listen to sermons. You need to start reading books about the Bible. It’s a fascinating and wonderful journey when you reach a point where you think, “I now understand the overall trajectory of the Bible.” That doesn’t come quickly. It took me many years—through seminary—to see the unity of the biblical message.