I will be visiting the four Walt Disney World parks during the early part of October.

What should I expect for crowds?

Since I'm not staying on property how can I get a Magic Band?

I'm not sure why the crowds. I think it's a relatively dead season during the day.

The Magic Bands can be purchased at the park or online. I think they're about $12.99.

Uh...that ends with Columbus Day weekend. That place is a zoo that Friday--Monday, as are most seasonal parks....

So expect big crowds?

Friday through Monday, yes...

I was there Columbus Day weekend last year. Crowds were up, yes, but not unbearably so or at their summer or holiday levels. I'd expect a 6/10 in terms of crowds. Even on slow days at Disney, crowd sizes rarely get below a 4/10. Utilize the Fastpass + early in the day to maximize your ride time and the rest will fall into place.

Yes, I saw that Undercover Tourist had it at a 5/10 those days.

I would caution using Undercover Tourist, I have seen multiple times their recommended days be horrific in the parks.

easywdw.com has some of the best advise, crowd calendars, plus daily touring plans all for free. I attached the crowd calendar for your quick review, but follow the link to the full month and day by day breakdowns. http://www.easywdw.com/calendar/october-2014-walt-disney-world-crowd-calendar/#more-13188