Kidz Therapy is a wonderful resource for information on a wide range of topics, and they have released a very helpful article on children returning to school. There are six tips for helping students return to the classroom. While it is aimed at slightly younger children, there is still some great advice in there.
You can read it here: https://kidztherapy.co.nz/articles/six-tips-to-help-your-child-survive-back-to-school-anxiety/