My very clingy, very tall 2 year old who has mild SPD on her first trip sat next to me on all the rides (and honestly, she's still velcro at 6 haha). I told her it was the rule and then I'd just throw my arm around her, or link arms with her if I'm filming, but what helped most was majorly prepping her. Youtube is full of full ride and first person experience videos where they can see other kids enjoying themselves. Watch them sitting beside your kid/s so they know EXACTLY what will happen each and every ride and that everything is safe. Yes there might be some times (like when Tigger pops up in Pooh or the heffalump smoke puffs) where you might end up saying the SAME thing each ride (Where's Tigger? There he is!) but it can make it more fun as a memory too.
The other things I did was bring glow sticks for dark ride/scary emergencies (the bracelets are wonderful and don't distract anyone else and when we were stuck on the Ariel ride in a scary part for 30 minutes these were a lifesaver), noise reduction headphones just in case, and a stroller where a kid feeling sensory overload can zone out for a bit. If there was a ride she didn't feel safe going on after seeing it, we skipped it until another trip (Peter Pan for example we only finally went on last trip because Hook for her was too scary the other trips).