Job fairs are held in March, bring a filled out application with you. The interviewers hate it when you have no idea what you're applying for.
Find a friend who has had the job you want (there are hundreds of current/former employees from past summers) and ask them to tell you about the job.
Don't answer "I don't know" to a question, say *something*! For instance, "Can you give me three words you'd use to describe yourself" should not be answered with, "No, I'm sorry."
Before coming in, think of customer service you've experienced at other places and how you could apply what you've seen to Wild Island.
You will absolutely be offered a job if your interviewers can connect with you on a personal level. Tell them about your experiences, things you like, things you don't like, what has helped shape who you are. Have memorable answers so that 300 applicants later your interviewer wants to put your application into the "yes" pile.