Stealing in this context could be using a theme, idea, structure, rhythm.
Here’s one way to ‘steal.’
Choose a line from a picture book you love and use it in your own story.
Later you can—and maybe should—change the sentence. But for now use it as a jumping off point for your own story.
Here’s one to start you off:
“You’re a big boy now,” Granny says. “Time for you to learn.”
—From Soul Food Sunday by Winsome Bingham (Illustrated by C. G. Esperanza)
What is your protagonist ready to learn?