The first act is gymnast Polly Prattle. She's walking on hers hands. Wow, that's pretty impressive! But Polly is "chasing rainbows" if she thinks she can beat me. "Chasing rainbows" means
trying to achieve something that's unrealistic; even impossible
I'm feeling good. I'm not even a tiny bit nervous. I'll just "chill out" until it's my turn. "Chill out" means...
relax
Here comes the second act. It's the Thompson triplets' marching band. I don't mean "rain on their parade", but they don't stand a chance against me. "Rain on their parade" means ..
to spoil that person's pleasure or plans
I'm feeling great! No one in this show can possibly have a better act than mine. I have it made in the shade. Made in the shade means...
to be in an ideal situation. easy
Look who's on stage now. Gabby Gates plays the violin every year. She's not bad, but she never wins. And with me on the scene, I don't think she'll break her "dry spell" today. "Dry spell" means ...
Long period without success