I Need Outfit Suggestions Please?!?

Aloha, I'm going to Great America in California tomorrow! FunFunFun! But the BIG problem is I have no idea what to wear. I was thinking a summery dress with some leggings that are a bit below the knees, but I wouldn't want it to go flying right? Haha, also, I'm going with my school. It's a private school. So it has to be appropriate. Like, short shorts are a big no no, and shoes. I was going to bring flip flops and take them off on the rides. If that's okay. Lol, and I don't have a big collection of shoes...So yeah. And I live in a most of the time cold city, so I don't have much summery clothes. In addition, I have KP. It's also known as the chicken skin, etc. And it's really embarrassing to show my arms. It's on my upper and lower arms. And nothing above the knees please. ._. Finally, I'm only fourteen. So keep it age appropriate! Thanks in advance and God bless!