Not autistic but highly sensory sensitive.
A few tips.
First, wear comfortable headphones. Wired ones should work in most modern aircraft (not like the old days).
If you're going to use a phone/computer, then I recommend bluetooth for your comfort.
Some people like noise canceling headphones. They give me a headache, but your mileage may vary.
I find it's hard to read on a plane due to space, so I prefer audio entertainment.
Bring water. Drink lots. If you don't like water, flavor the water.
Aisle seats make for being jostled, but if you have to pee a lot, it's worth it. If not, window for the sensory benefits of a wall.
Bring favorite snacks.
If it's a red-eye, take a sleep supplement like melatonin or 5-HTP.
Any other concerns?