Good morning, Eileen! I appreciate waking up and wanting to head to 
Walt Disney World Resort.
I wish I could say it's an April Fool's joke for you, but the ticket system currently shows tickets for 
Magic Kingdom Park are sold out today. At this time, you won't be able to purchase a ticket online or at Walt Disney World. It could change throughout the day if space becomes available, but this is a busy week with many schools on Spring Break following the Easter holiday. 
There are so many options to have a magical day. 
Theme park tickets are available for 
EPCOT, 
Disney's Hollywood Studios, and 
Disney's Animal Kingdom Theme Park.  
You could purchase a ticket to one of these parks with the 
Park Hopper option. With this, you might be able to enter Magic Kingdom Park later in the day, but this is subject to the crowds. There is no guarantee entry into Magic Kingdom will become available. At worst, you enjoy another park, but if your heart is set on Magic Kingdom, that wish may or may not come true with a Park Hopper ticket.
I do hope you have a magical day. With the 
EPCOT International Flower & Garden Festival in full bloom, you might find a bee-utiful day awaits.
Adventure is out there!
Jana