What is "office attire" for girls?

I'm a 16 year old girl and I just got an internship at my local newspaper. I really want to be a journalist and this is an incredible opportunity for me. I'm a staff writer at my high school's newspaper and our advisor and editor-in-chief told me that at the newspaper I am going to be having my internship at people dress in "office attire." What is that exactly? I figure it means no jeans. I really like to wear dresses/skirts and low heels/flats. Will I be able to?