I'm going to holiday world,please help me?

Okay so I live in Indiana right? Right. So the only place to go like a big water park is Holiday World. I get to bring my friend, Abbie. She is 10. Im 11. My Brother is also coming and he is 8. He's tall enough the ride all of the rides too. I'm REALLY scared of rollercoasters and my friend is to, but she'll ride if I do. How can I get over my fear?!?!?! And is the Pilgrims Plunge Scary? Also Is the Wildabeest Scary? Thanks. And please dont call me stupid or say im to young, cause i really dont care. And My brother is like super physiced about it and I'm like OMG HOW ARE YOU SO EXCITED YOUR 8 IM 11! Please help. Oh Yeah And Im Leaving This Thursday... Its only a 3 hour drive and im leaving saturday.