I am posting in AIBU for traffic, but please be kind, this is my first post ever here, so trying to do it right 
I am starting a new job tomorrow, after I had a job that I hated, I have been pretty much bullied, and now, admittedly, my confidence is a bit shattered
So how do you act on your first day? How do you blend in, how friendly do you need to be?
Any tips for a successful first day? Also, what do you wear? I know this is not style and beauty but it would help. It's an office job, non facing customers (my first ever without customer contact yay!)
Thanks everyone