Hi, Samantha!
Yay! You're sailing on the Disney Dream -- I can't wait for you to have your turn aboard this magnificent ship!
Disney Cruise Line ground transportation is available back and forth from the Walt Disney World(WDW) Resort to the Port Terminal at Port Canaveral for about $70 per person round trip. You will need to book your ground transportation as far in advance as possible of your sail date by calling (800) 951-3532. Once you check into your WDW resort, you will be instructed about when/where your motorcoach will pick you up, and you'll receive detailed instructions about your luggage, too.
For Disney cruises, I have actually had bell services pick up our luggage the prior evening (before midnight) and very early the next morning (before 8 a.m.). Either way, you need to make sure you have all you need for the day laid out the night before and/or packed in your day (carry on) bag.
As far as the ground transportation schedule, it varies according to how many other guests have booked transfers and from which WDW resort. You may board as early as 8 a.m. or as late as 10 a.m. -- with a few other stops to pick up guests at other resorts. On Disembarkation Day, your motor coach will be waiting on you once you exit the port terminal after US Customs clearance -- which should be around 9 a.m. You should be back to Pop Century and checked in before lunch.
I hope this helps. Have a wonderful day and a magical vacation. Bon voyage!
Andi