Why did Maxwell leave Freak alone in the Mighty chapters 1 2 3?

You're likely referring to the book "Freak the Mighty" by Rodman Philbrick. In chapters 1, 2, and 3, Maxwell (Max) doesn't leave Freak alone. He and Freak (Kevin) are inseparable and spend all their time together.

The story actually begins with them already being close friends. Max is a large but insecure boy, and Freak is a small but brilliant boy with a physical disability. Together, they become "Freak the Mighty" and embark on adventures to overcome challenges and prejudice.

If you have a specific scene in mind, please provide more details so I can help you understand why Max might have seemingly left Freak alone.