Hi, Carolyn! How exciting that you're traveling from California to WDW! Chances are, you're probably a Disneyland guest looking forward to seeing its vast counterpart in Florida. If you haven't ventured to WDW already, I think you'll be amazed.
From the
Disney World site, you can scroll over to Parks at the top of the page and click on any of the four theme parks or two water parks. Once you are on a page for a park, click on the Calendar on the left side of the page. You can then go to a specific month and click on a specific day for the scheduled events.
From a cursory glance, it looks like Fantasmic! is playing twice while you're on Spring Break -- on April 5 and 7, both at 8:30 p.m. Remember to get there early for a great seat, or you can obtain designated seating by reserving a
Fantasmic! Dining Package. Of course, as with all schedules, entertainment times/days are subject to change. Therefore, it's a good idea to bookmark the various parks' calendars to check schedules periodically. Of course, a times guide and map will be your best friends once you enter each park!
I hope that I've helped make your planning fun and easy. Let me know if I can do anything else to answer your questions. Have a wonderful day and a magical vacation!