Watch this video on the 5 tips for creating a children's book with Canva!
Here's the link below:
https://youtu.be/bdLxMpAIcg8?si=eKFUD957kcKePrXF
Use Google Bard to write your story based on your prompt. Make sure that you check it for playgerism before uploading the files into your preferred platform. You must notify the platform that your story is Ai generated content. (Read, the platforms rules on this topic beforehand).
Examples: Amazon KDP
There many other self-publishing websites out there, so do your own Reasearch!
Other then that get creative with your story!