I just made my first fondant cake yesterday and it looked pretty good. We haven't eaten it yet, and today I looked at it and it is starting to pucker in one place. It looks like it just has a big air bubble underneath it. Why did it do this? Now it looks like my cake is lopsided. I'm so sad.

Did you smooth out the surface of your fondant after applying it to the cake. Sometimes air can get trapped under the fondant. Other trick to get the air out is to prick the fondant surface with a pin, and smooth the air pocket so the trapped air can escape through the small hole.