They are separate entities and you need to purchase from each website or by phone. Periodically they have specials with either their on site or partner hotels.
Universal Studios is an entirely different from Disney's Epcot, but you will find that both parks don't really discount their tickets anywhere so the best way to purchase is from their individual websites. This is the most trusted way to purchase. If you are staying at any of their resorts you can also purchase them at the front desk when checking in.
Yes, defiantly get the fast pass.
Go on to the website.. go on line now to purchase for tomorrow and get a fast pass
Online and watch out for specials in stores.
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