Hi Amra, welcome to planDisney!
September is a fabulous month to visit Walt Disney World Resort. The EPCOT International Food and Wine Festival delights the taste buds and the seasonal decor at Magic Kingdom Park is pretty spooktacular.
As you experienced, single-day tickets are not currently available via the
Walt Disney Travel Company. You can, however, book single-day tickets from
Disneyworld.disney.go.com as soon as you enter the United States. In addition to valid admission, all Guests must also have a
theme park reservation to enter the parks. As such, it's imperative that you consult the
theme park availability calendar before purchasing your tickets. As of right now, all parks are showing availability for all dates in September.
If a park does not have availability, Amra, it's good to know that Guests with Park Hopper tickets can typically hop to any theme park after park hopping hours begin at 2:00 p.m. You only need to make a theme park reservation for the first park you enter. Keep in mind that Magic Kingdom Park closes at 6:00 p.m. on nights that
Mickey's Not-So-Scary Halloween Party takes place.
I hope this information helps you plan your practically perfect Disney day. Purchasing Disney Genie+ service the morning of your park day via the Tip Board of your My Disney Experience mobile app (three small lines at the bottom right of the home page --> Tip Board) will also help you maximize the magic on your Disney day.
Choose magic,
Jennifer