Children recognize and relate to emotions expressed by characters, and relatability is important, but relatable doesn't have to mean identical. Maisy books are a great present-tense example.
All characters should be drawn with both good points and weaknesses. If your character talks to himself or does a lot of wondering aloud, he needs a friend to talk to.
Create a book dummy and fill in the pages with your idea. I took the legend of Hercules, combined him with a wild turkey chick, and voila.
Pack picture books with lots of text. Tighten up your draft. Is the main character the central focus on every page, with everything happening to them?