Sink or Swim Time

I wasn't expecting to be given so much responsibility so quickly at my new job.  I have only been there 4 days and I am tasked with opening the store by myself on Valentine's Day.  Granted it is a drug store and I have not witnessed a lot of traffic this week, I am still a little nervous about opening the store when I have not completed all of my training.  I'm not too sure this is being done because the manager wants to test me or if he really has no choice due to limited staff.  What I do know is that it's sink or swim time and I don't have a life jacket.