What do you need to know to fly a Cessna?
You're on the right track, but let your instructor guide you along the path of righteousness or you'll end up thinking about all the stuff rattling around in your head instead of listening to what they're telling you while they're trying to show you how to fly. Day 1 is largely just familiarization - you're not going to need to know all that detail. They'll have a syllabus that will include everything you need to know, and they should be able to guide you on what'll be good to focus on for the upcoming lessons.  The private pilot practical test standards are a great preview of what will (eventually) be expected, and if your ground school works you should be through the written and aware of any weak academic areas soon enough to correct any knowledge deficiencies that may bear on your flight training.  Definitely read the POH cover to cover so you know what's in there (but you don't have to memorize it all!), and ask your instructor about anything that doesn't make sense.  Listening to the tower on a handheld or through LiveATC.net may be useful (you'll find they're probably doing the same thing over and over and over) to understand what to expect, and the Aeronautical Information Manual is full of useful information that may go beyond what was specifically covered in ground school or on the written.  ATIS and/or ASOS/AWOS broadcasts are usually available on the phone, so listen to them until you "get" it all.  That should save time in the airplane.

The instructor should also cover checklist procedures, and will know what local examiners expect you to do to pass.