The first time we took DD to Disney World she had just turned 3 and hadn't been diagnosed yet. It was rough, I talk about it here:
https://www.disboards.com/threads/stroller-for-7-year-old-w-autism-yay-or-nay.3935927/post-65225702
and here:
https://www.disboards.com/threads/s...can-it-improve-with-age.3901786/post-64473348
tips I gave another poster:
-Large disability stroller with full pull down shade tagged as a wheelchair so we could take it in lines with us
-Stroller accessories: fan, rain cover, cup holder, etc.
-slip on tennis shoes so they can be easily removed when sitting in stroller
-phone or similar device with downloaded
youtube videos, movies, books, and music (with backup battery for charging)
-headphones that can double as noise canceling and connecting to previously mentioned device
-sunglasses, baseball cap, and lightweight spray on sunscreen
-several packed snack options and a spreadsheet for acceptable food locations (DD has food aversions)
-change of clothes in case something becomes dirty/wet/uncomfortable
-let the kids each pick a certain number of rides and space them out throughout the day to pace their preferred/nonpreferred activities, keep them informed of the plan for the day so they can be prepared and less anxious about what to expect (we also found DD was more flexible when plans had to change if she was kept in the loop and allowed to help make new plans)
-late start to avoid the rope drop crowd and packed buses (during spring break this looked like us arriving in the parks between 9:30-10:30)
-break around 1-4 for lunch/nap/afternoon swim and come back for or after dinner if up for it
-leave either before fireworks or an hour after it ends if possible to avoid crowds
-have a no park day or 1/2 park day every third day (we also book fireworks dessert party specifically for the non-crowded viewing space)
-keep as much of your at home routines as possible (for example is there a specific show/book/song they do at bedtime?)
-We used to use Fastpass like crazy before they got rid of it and now we use
DAS