Interview Tips

I have an interview with a boutique Philadelphia firm as an IB analyst in a week and am really freaking out. As background I’m an MSF student (3.6 GPA) and a Level III candidate with 2 years in corp fin doing credit analysis. This is the only interview I have for the forseeable future and I’m extremely panicky about not F*ing this up so any advice or prep tips would be appreciated. I’ve never interviewed for this type of position before and have no idea what to expect. I do know that my most likely competition is another guy from the same program with his CPA who worked for a big four firm for 2 years and currently holds a 4.0 GPA, however I’m more active in programs such as the student managed fund outside of the core curriculum. How should I approach the interview in general? Also, what specific strategies should I use to differentiate myself from other interviewers?