Start by thinking about their personality, likes/dislikes, and how they would react to certain situations.
When crafting a story, one of the most important things is choosing and creating interesting characters. Your main character(s) are what drive the plot. You need to know who your protagonist is and the obstacles they will have to overcome. Once you’ve chosen your character(s), it’s time to develop them further. Start by thinking about their personality, likes/dislikes, and how they would react to certain situations. Next, consider what they do for work and where they live–the more details you include about their lives, the more realistic your story will feel.