Hi Samantha,
Thank you for sending a question our way. We've all been there with planning the first Walt Disney World trip and know how overwhelming that can be. Most likely, the crowds will be quite similar visiting the last week of October or the first week of November. On Halloween, there is often a large crowd at the Magic Kingdom for
Mickey's Not so Scary Halloween Party (separate ticketed event), but this may be an event your son would enjoy. How often can you trick 'n treat at WDW? In fact, the entire family can join in! It is offered on other evenings as well.
Also, at Epcot there is the
International Food & Wine Festival going on which gives guests a fun way to sample international food!
If I were booking the trip, first I'd keep checking the
Special Offers from WDW; free dining has been offered in the fall in previous years. I would aim to have a trip booked at least 6-9 months prior to when you'd like to visit since dining reservations can be made up to 180 days in advance. Some restaurants are quite popular and fill up quickly.
If you haven't ordered the
free planning DVD from WDW I'd do that as well; it will help you with your initial planning. Also, we are here to help; don't hesitate to send us many questions. We love being able help guests!