Were they made up for entertainment ?
It might interest you to know that there were eye witnesses to what we mistakenly call creation. They recorded their observations as best they could, carving some records into stones and passing verbal accounts from one generation to the next. It has taken a very long time to interpret these records because they don't describe anything we have seen. For example the legend of the dragon is carved into rocks all over the world, but it is only recently that anybody has noticed a natural effect that fits that description. This is a long book because it tries to cover everything completely.
God speaks to us in our own language. We often use figures of speech that are not literally true, and so does God. We might tell a story to get a point across, and God does the same thing. We talk about "corners of the earth" and "four winds" and moving sun, and so does God. Noah's flood is an especially interesting example because no evidence has ever been found, and yet people all around the globe recorded a flood that year and they all agreed on all the details. The book I linked above explains that too. You will be surprised to learn what actually happened.
I would say if they were made up for entertainment, people all over the world would not be able to apply the principles and come out with the same result of success.
There are many stories that have are historical accurate. Many stories man has said never happened or people didn't exist only to find through archeologist fragments and evidence of the existence of what was thought to be just a story. Some are stories highlighting the benefits or consequences of listening to God. There are parallels highlighting principles that we should follow. Since as people we really think in pictures, Jesus was known for teaching by means of illustrations. This helped people visualize and to get the point that he was making. Examining the bible is the one of the most exciting things I have done and its a continual process of learning. The benefits out weigh anything. I encourage you to do so yourself. If you would like to know what the bible says regarding specific questions, you can visit jw.org and type in your question in the search box.