I was pretty nervous starting my new job. I was not sure what to expect
Wow, congratulations on getting a new job!  I think butterflies are good to have to make us do our best and it shows your job is important to you and you want to do a good job.  What do you do?
Its in production
That sounds fun. Have you done something like it before or is the whole kind of job new to you?  Good luck and I know you'll do great!  Act confident even if you don't feel like it. Sometimes that can help.