In the beginning of your story you introduce the character(s) (who is in your story) and the setting (when and where they are). The setting could include time of day, weather, and even the mood.
Example: This is a story about a dog named Bear. She was a happy dog that had a whole house to herself! She would spend her day just lying about on the couch and other pieces of furniture. She would sleep all day and then, in the afternoon, wait at the top of the stairs for someone to come home from school.
Now we come to the middle of your story. In the middle of the story, for a climbing story, is where we are introduced to the problem.
Example: Then a pandemic hit. A pandemic is a really big sickness that people all over the world can get. To keep everyone safe, all the people were told to stay home. Only essential workers were allowed to go out. People could get groceries and dog food and treats (thank goodness) but otherwise they should stay home. For Bear this meant she no longer had the house to herself. She now had to share it with the rest of her family. Naps were interrupted with books being read out loud. People were sitting in her spot. Her hair was growing long and she looked a mess. The couch was no longer comfortable.
At the end of the story we solve any problems. Maybe, we explain how the characters had changed. Maybe, the characters had grown or changed. Maybe they learned a very important lesson.
Example: At first Bear was confused and angry with all the changes. She no longer would lie on the couch and sleep because there was too much action in the house. She was constantly distracted by all the noise. After awhile everyone settled into a routine. For Bear that meant three walks a day! She was so excited and happy. She stopped wishing the two leggeds would go back to school. She was happy with the new daily routine and she still got to spend time on the couch. Although, she did really want a haircut but she was told it would have to wait until the pandemic got better and life was more normal.