Mine's tomorrow and I'm nervous, too!
But I'm looking forward to it.
I emailed the (veteran) crew chief who I'll be working with, and he told me not to worry about anything, just to have fun and be ready to learn.
I can do the former, and I am definitely the latter, so it's all good.
What I
really want is the chance to work with Jeff someday so I can overrule him.