I think going with him to the school so he can have a walk threw an to see everything, meeting the teacher. For my oldest we got her a folder an a note book an pencil with a character she liked on it or decorated in hopes to make her feel excited for her first day. We also read some stories about the first day of school. Had a new outfit she picked out ready. For the first day her dad went there for lunch to eat with her.. I think that helped her alot