Many autistic people struggle to know what they can ask for when offered help. For this reason we often suggest the use of an accommodations checklist. This is something that a school could provide to the autistic person or parent to offer different kinds of accommodations/adjustments. This resource covers some ideas of things you may consider putting onto such a checklist.
Rights at school
This resource outlines children's rights at school, and what to do if those rights are not being respected.