Off topic need help

I started a new job and feel like I'm screwing up left and right. I haven't worked in over ten years bc I have been able to be a stat at home mom. It's in a very small office, and I feel like a moron. I don't know the typical office lingo.  I'm so confused. I want to stick it out but how can I approach the boss and say listen I need help in a professional way?