Private Equity Intern Interview Help

I've just received an interview with a boutique PE firm. The interview consists of 30 min with a director followed by another 30 min with an analyst. was also told that the interview consists of a case! Currently a 2nd year accounting major and have no experience/knowledge about pe. however i do have very limited knowledge of finance (took 2 corporate finance courses) and dcf modeling experience. would appreciate for any advice on how to prep for the interview. very worried and dont even know why I was chosen in the first place! i don't expect to get the job but def don't want to make a fool of myself. any help is appreciated! thanks :)