Trying out for the first time at my community theater?? Can you give some good advice?

Anyway, I just found an audition posting for a relatively local theater for A Christmas Carol and I really think I should audition. If I don't get a role, I think it would be a great experience just to put myself out there. The audition is in about a week and it's just cold reading from the script. It says that there's "no preparation needed." I really want to audition but I'm also really scared and still feel like I'm really "new" to the whole acting thing.

I'm just looking for a little encouragement and advice on how to get over the fear and also how to handle a community theater audition and what to expect. I have my acting class tonight so I'm also planning on discussing it with my teacher, but I would really love to hear from this community that has always been so giving in the past :) .