Here is a timeline of the story of the Bible. It is a very basic, simplified outline, that divides the story into 5 chapters, with the middle chapter (about Jesus) being the very center. This diagram also makes it clear that the mission of God is to restore His creation.
The two-coloured line represents those who resist God (black) and those who surrender to Him (green). These two lines are intertwined during this period between the creation and the new creation, but at the end God will separate them. For a season, what we call ‘heaven’ is the dotted line at the top. To say that we ‘go to heaven’ is better understood as we go to be with the Lord, and will one day live with Him in His new creation.
Understanding Jesus is essential to understanding the old testament and the new testament. I actually recommend that people first read the 4 gospels (Matthew, Mark, Luke and John) before tackling the rest of the Bible. There is lots of difficult stuff in the Bible, and I think it is best processed through Jesus. He is the fullest, the best revelation of God. If we want to know the heart of God, look to Jesus.