Hi, Kerry-anne!
I'm guessing that your Walt Disney World Resort reservation includes the
Magic Your Way Premium or Platinum Package. Preferred Fireworks Viewing for
IllumiNations: Reflections of Earth at Epcot and
Wishes at Magic Kingdom is included in these two levels of vacation packages. You should receive a voucher in your vacation packet for these two experiences. Advance reservations are required and even though there is a designated "preferring viewing" section, I would still recommend arriving early for the best spot.
If you've booked your vacation directly with Disney, I recommend calling the Walt Disney Travel Company at 407-939-6244 to speak with a Cast Member for further details on the
Magic Your Way vacation package. If you've booked through a travel agency instead, I would definitely give your agent a call. You'll want to clarify which specific type of vacation package you've booked (Premium or Platinum) and confirm that the vouchers will be sent by mail along with your travel documents.
I hope this helps! Please don't hesitate to write back with any other questions as you continue to plan your visit to The Most Magical Place on Earth!