Hi Lisa!
If you're not staying on a resort, and only plan to spend 1 day at Animal Kingdom and 1 day at Magic Kingdom (home to Mickey's Not So Scary Halloween Party), I would do the following:
- Purchase a 1-day Magic Your Way base ticket
- Purchase tickets to the Mickey's Not So Scary Halloween Party
The 1-day Magic Your Way base ticket will grant you access to Animal Kingdom, and the Mickey's Not So Scary Halloween Party tickets will grant you access to Magic Kingdom (if you purchase tickets to the Halloween party, you won't need to purchase separate tickets for theme park admission as long as you attend during the party time).
If you're in Orlando from October 9th-17th, I would plan my Magic Kingdom visit to coincide with one of the days of the Halloween party:
Mickey's Not So Scary Halloween Party is scheduled on the 12th, 14th, 17th, and 19th of your stay.
This would give you the most bang for your buck and possibly save a few dollars for the remainder of your trip! :-)
Have a terrific time at Disney!