A lot of schools have strong disability service departments, so I would start by identifying schools of interest, and then interview them as to what support services they have.
I would also consider what your child's needs will be. My son really does not want support services, and only registered with the disability office when he found out there could be handwritten blue book tests in courses (he has disgraphia and needs to keyboard everything). When he was 17, I was very concerned about him heading off to school away from us, but somehow by the time he actually left he was ready. Last year he actually lived overseas for a year of schooling abroad, without campus housing. I could never have imagined. Still, back up options are good; you don't want your child to experience harmful levels of stress (stress is not something my son can navigate AT ALL).
My son is in the University of California system, btw.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).