I have been to 2 of these already. Meeting with 5 or 6 faculty is really the norm. You don't just meet with your POI because the faculty want to get a feel for you from different people's perspectives and its good for you because you get a lot of perspectives about the program. These meetings may seem kind of scary, but they really arent. The faculty like you and want to get to know you, you wouldn't be there if they didn't. They don't try to stump you with their questions. They typically ask what your research interests are, what you've done, why their institution, etc. They will also give you the opportunity to ask them questions both about their research and the program.
Don't stress...do look into the research of the people you are meeting with, but dont worry too much about it. You will do fine.
Good Luck!