what book should i read first?

I'd start with my favorite book, the Gosple of John, and I recomend the Zondervan NIV Study Bible.

I personally love the book of first John, very loving and tender, lots of Gospel; it's as if God wrote us a love letter. Gives us everything we need on how to be more Christ-like which makes it so very relevant for starting the Christian walk. Then I would go to Proverbs, great maxims for living a God-pleasing life as well. I love all of the Gospels, I particularly love Matthew chapter 5, the greatest sermon ever spoken by the greatest man who ever lived, which also contains all of the tools for walking as a Christian. Also, Romans is a great overall summary of the Gospels, so that would be a great place to start too...