Welcome to planDisney, Natalie!
October is one of my favorite times to visit Walt Disney World. The weather is comfortable and the Halloween decorations around the parks are awesome! Make sure you stop by
Main Street Confectionery at Magic Kingdom Park or
Disney's Candy Cauldron at Disney Springs for a delicious caramel apple.
Mickey's Not-So-Scary Halloween Party is a special event that requires a separate ticket. If you purchase a ticket, then you'll be allowed into Magic Kingdom Park from 4:00 PM (although the actual event doesn't start until 7:00 PM). If you'd like to enjoy Magic Kingdom Park earlier than 4:00 PM then you'll need to purchase a standard theme park ticket and make a theme park reservation for Magic Kingdom Park.
On nights when there is a special event, like Mickey's Not-So-Scary Halloween Party, Magic Kingdom Park closes early (usually at 6:00 PM). This sometimes means that Magic Kingdom actually has fewer crowds during the day. So it can actually be a good day to visit, even though it closes early.
If you do choose to attend Mickey's Not-So-Scary Halloween Party, you'll have an amazing time! Disney's Not-So-Spooky Spectacular is uniquely wonderful. The Hocus Pocus Villain Spelltacular is not to be missed. And Mickey's "Boo-to-You" Halloween Parade will captivate you from start to finish. Plus, you can even dress up for the event! How cool is that?!
I hope that's helpful, Natalie. Have a great time, whatever you do.
Mike