First of all: Good luck! I'm starting there as a parade/character performer in the near future and the audition is alot of fun and alot less stressfull than you imagine. Just keep smiling and imagine you're int the park performing that's my best advice
Yes the audition will be in English.
I went to a proffesional musical theatre school so I just took my normal CV. So if you're a performer just take your normal CV
! if you don't have one google CVs for auditions and that should give you a basic idea.
But basically it should include:
Name, Phone number, email
Profile: height, languages, possibly playing age (kinda irrelevant here), some girls put dress size
Training: say you did a course somewhere be it fulltime or parttime or just for the summer. Dance, theatre, acting
Experience: any form of performing experience you have be it professional or amateur.
Skills: Dance styles you can do, singing, improv skills, gymnastics, etc maybe youre really good at rollerblading.
CVs are less important at the actual audition but it could make a difference if you get put in the talent pool. So it's def worthwhile putting some effort into it looking good and attractive
Hope that helped!