It doesn't hurt to research the company before you go in, often times the interviewer will ask what all drew you to apply and they want to hear more than "I wanted an internship in finance so here I am." While interviewing for my finance internship I was asked "What does finance mean to you?" and a few questions about data analytics and previous experience with number crunching software and query building in SQL (I admitted to knowing nothing about SQL and still got the internship).
If your college has mock interviews that you can schedule (I'd check with career services or the academic advising office if you're unsure) they can be really helpful and give you pointers on your answers. If not, have a friend or professor, or really anyone pull together a list of interview questions and dress up for your mock interview like you would a real one. The more interviews you do, the more at ease you'll feel.