PVN in LPN tenessee technology center?

Okay so I just started classes at the Tennessee Technology center in Union City Ive been studying like crazy my older sister went through a program in another city. Our first test is gonna be on the PVN. How hard is it? Its so hard for me trying to remember the dates. I know all the facts its just the dates confuse me is this important? And also how hard is this course, from what ive been reading I am terrified!!!!! Please help