YOU ARE NOT REQUIRED TO BUY PARK TICKETS. You do not need tickets to get to the ceremony and reception venues. You do not need tickets to enjoy complimentary on-site transportation services. The only reasons you would need a ticket are if you plan on attending the bachelor/bachelorette party (Epcot) and for your own enjoyment.
Other things to do in Orlando:
Our wedding guests staying on property may take advantage of Park discount tickets through calling: (407) 827-6799, or via https://disneyurl.com/Weddings.
Make a theme park reservation via the Disney Park Pass system. To enter a theme park, all Guests ages 3 and older must have a park reservation in addition to valid admission for the same park on the same date.
We recommend downloading the 'My Disney Experience App"
HOW DOES PARK HOPPING WORK WITH PARKS PASS?
-Book a parks pass for any of the four Disney World theme parks for your date
-Visit the park you booked on that date
-At the start of park hopping hours (usually 2 PM), go to any of the three other parks
You don’t need a parks pass reservation for any parks you visit after 2 PM after you visit your first park, however, you do need to start your day at that first park with a parks pass reservation. You cannot simply show up at any park after 2 PM if you haven’t first used a park pass reservation to visit a park.
For more information please visit: https://disneyworld.disney.go.com/experience-updates/park-reservations/
https://www.mousehacking.com/blog/disney-world-park-reservation-system-what-we-know