Just let your imagination run wild and jot down the first idea that comes to mind. It can be a character, a setting, or a plot twist.
Well, start by thinking about something that really interests you or something you've always wanted to explore. Maybe it's a magical world, a historical event, or a future technology. Then, build on that initial thought and see where it takes you.
When you have that fantasy, try to focus on one aspect that excites you the most. For example, if it's a character, describe their appearance, personality, and goals. That could be the beginning of your story.