There are some great books for artist. The Artist Way by Julie Cameron has a ton of exercises that helps you become creative. It’s a 12 week journey to help you get unblocked when you can’t think creatively.
Here’s one of my creative exercises. Look out the first window that’s near you. Describe the world outside the window. Make each person you see a character in your story. Tell us what they want and what their “issue” is.
Now tell me about your story’s protagonist. You can even choose tell the story fro the perspective of a character that is looking out the window. Maybe it’s a world she doesn’t belong in it’s all up to you.
Be creative and have some fun.