Hi Sonia!
Thanks for sailing by! One of the (many, many) things that differentiates Disney Cruise Line from other cruise lines is the fact that
soft drinks at meals and at the Beverage Stations on Deck 11 on the Disney Fantasy are free. There is no need to purchase a separate soft drink package. Your soft drinks will be served in normal stemware in the dining venues. At the Beverage Stations, you will find insulated disposable cups for hot beverages (tea, coffee, hot chocolate) and more traditional disposable cups for cold beverages (soda, water, etc.) Disney Cruise Line asks that you use a fresh cup each time you get a beverage for sanitary reasons.
However, if you are a fan of Disney-themed (and, more specifically, Disney Cruise Line-themed) cups and other merchandise, you will find a wide variety of souvenir cups in the gift shops on board. I have amassed quite a collection of insulated cups (including Tervis Tumblers) and mugs that I use at home. Each one takes be back to the nirvana that is a Disney Cruise Line voyage when I'm enjoying a beverage back here in reality!
Have a wonderful trip!