The Gospel of John is a great place to start reading the Bible. The Twenty-One Day Challenge provides a suggested way to read the Gospel of John a chapter a day. You can subscribe by email to have a reminder sent to you every day. The Gospel of John contains a narrative of the life of Jesus and is easily understood. But perhaps the best reason is as the book itself states:
Jesus performed many other signs in the presence of his disciples, which are not recorded in this book. But these are written that you may believe that Jesus is the Messiah, the Son of God, and that by believing you may have life in his name. (John 20:30-31)
As you get started, you may like to have an overview of the book. The Bible Project offers a nice two part video overview. The total running time is roughly 19 minutes.
Skip Heitzig offers a summary of the Gospel of John in his sermon series The Bible from 30,000 feet. You can watch that here: