Understanding scripture is as simple as learning to love the Lord completely, and loving and accepting the people God created. It is also so complicated that men have spent an entire lifetime devoted to understanding it and still have more to learn.
It helps to know how it is divided. The first five books tell of God's principles, then the rest of the OT show how those principles work in life at that time. It takes in 4,000 years, with lots of changes in the world during all that time. Then comes
the three years that Christ lived on earth.
From almost the first years of the earth men didn't listen to how God created the world to be.
God started a new race we call Jews to show the world God. Every race but them made up their own god, or they became Jews to worship the true God. The rest of the OT scripture tells about this, with the Jews not doing a very good job of being true to the Lord.
The last part of scripture is the story of men taking the principles we learn in the first five books of the bible to all the races that weren't Jewish. The main point of these letters is instructions in following God's way without the cultural things the Jews did that God had given them to remind them of God's ways.
The problem with learning scripture is that the first five books are important but the people used to explain God lived in a world very different from ours so it is hard to understand them. To complicate it further, the original language used was Hebrew and it doesn't translate well. There are always layers of meaning in all it says, the main two is the simple telling of what happened. There is always a spiritual principle behind each happening. Everything is symbolic of some spiritual truth as well as giving the facts of a happening.
The ideal way to understand is to study the first fiver books first, but it is tough going. I use
www.torahclass.com to help, for it gives the culture of the people at that time and symbolic meanings of scripture.
Perhaps starting with Psalms and Proverbs would be easier, it gives what God is like. Once you understand the God the rest of scripture is telling us of it is easier to understand the message. You need to keep in mind that all scripture speaks of Christ. As an example, learning the sacrificial system is learning what Christ does for us as it is symbolic of Christ.