Hello Nour,
What a lovely day you have planned! I love arriving at Walt Disney World early in the day so we can get our vacation started!
If you want to
make dining reservations in Epcot, I recommend reserving something mid-afternoon. You'll have access to Magic Kingdom Park for Mickey's Not-So-Scary Halloween Party as early as 4:00 PM, so if you wish to arrive at that time, you'll want to make sure you don't feel too rushed.
That said, if your travel plans run later than expected, you won't want to stress about making it to your reservation, so planning an earlier meal may not be the best idea.
When we attend
Mickey's Not-So-Scary Halloween Party, we typically plan to arrive at Magic Kingdom Park right at 4:00 PM and eat a quick meal at
Casey's Corner or
Columbia Harbour House. Then, we can enjoy a few attractions before the party starts and be ready for a night full of spooky fun! Since you are attending the party on your arrival day, something like this may be a bit less stressful than a table-service meal.
Wishing you many happy haunts at Walt Disney World, Nour! Thank you for visiting the Disney Parks Moms Panel.
Andrea U.