I just booked my first solo for May. I am so excited to get to do what I want for once!
OOhh first timer...
Are you staying onsite?
If so, check out the EMH (Extra Magic Hours) schedule for the parks for the month of your trip. As a solo, you might be a morning person who can up very early and get to the parks and enjoy that benefit. Or maybe you are a night owl and can stay up late at night, enjoying it that way. Or you can do as some do, and stay away from the park where the EMH are, to stay away from crowds! Thats the beauty of a solo trip, you can do what ever you want!
Are you a fan of thrill rides?
If so, the Tower of Terror, and Rockin' Roller Coaster at DHS are amazing, make sure you check them out!! Expedition Everest and Dinosaur! at AK are also good thrill rides. Mission:Space and Test Track at Epcot are awesome too!
Like something a little more low key?
Then make sure you ride Soarin' at Epcot, The Great Movie Ride at DHS, and the Haunted Mansion, Peter Pan, It's A Small World, and Pirates of the Carribean at the Magic Kingdom. They are all great choices!
Check out all the shows, see if any would be what you might like to watch, or maybe the different parades at the parks, they are all fun. Make sure you make time for World Showcase at Epcot. It is so nice and interesting, plus you can find some of the best snacks from around the world there!
Do research, check out the Attraction videos on WDW's website, study maps of the parks before you go, so you have an idea of the layout, and remember.. you are at the Happiest Place on Earth, just enjoy yourself.