Place the main character from your story in a setting that’s not in your plot (the mall, a classroom, your own home, etc.) Write a scene in the First Person Viewpoint with your main character narrating his/her reaction to the setting.
Then write the same scene in Third Person Limited.
If you’re writing a picture book, try using the Omniscient Point of View for a draft to see how the book changes.
Is it absolutely necessary to treat all the characters the same, or can you better tell the story by following one character through the plot? Which will make