Hi Melissa,
Early october is an excellent time to visit Disney World. The weather is typically warm but less humid and the fall decorations are great. You will be able to enjoy the Food and Wine Festival at Epcot and of course, one of our favorite events, Mickey's Not So Scary Halloween Party.
A special admission pass is needed for all guests ages three and up and can be purchased by calling 407-WDisney or 407-934-7639. The ticket will allow you entrance into Magic Kingdom and all the evenings events including a special parade and fireworks show, trick or treating, entry into the numerous shows and attractions, unique performances available during these select evenings only and of course trick or treating in the Magic Kingdom.
Our family never misses an opportunity to celebrate Halloween with Mickey and his friends at this special event. There are a number of great shows, character meet and greets and of course an amazing parade and fireworks show that can only be seen on these few nights. The event is open to a select number of guests and therefore the crowds tend to be considerably less. This allows us to enjoy the attractions and shows with a shorter wait. We often can accomplish in just a few hours, what might take us a full day at Magic Kingdom. We love the fun and excitement of dressing up in costume and love seeing all the other amazing costumes of the other guests. The event has never been a disappointment to us and is always worth the separate entrance ticket. You can find additional information on the event
here.
I think your family will love the smaller crowds, shorter waits and special happenings and will have a boo-tiful time!