Well, I guess you made your inscription to a flying school where you'll have a real course frame with practice & theory. No need to worry about your first hour, and all the other subsequent ones really. Like SQ325 said, your introduction flight consists in giving you a first contact with the plane and make you discover the feel of the airplane. Your flight instructor will monitor your progress and performance and nobody will let you (or anybody) go solo or else if they don't feel you're ready.
BTW as a coincidence, I just did my first solo a few hours ago. And sorry to deceive you FlightSimFreak but we're both a bit some kind slow learner since I did it as well after 20ish hours and the standard is about 15 hours usually
. And I also took it off and (almost) landed it at the first hour. Must say, due to the kind of job I have, I can't follow a regular course, so I have to do the theory on my own with my books and fly when I can, which can be sometimes months apart between two sessions. But what counts anyway is how good, and especially how safe you are when it's time to pass your licence
. As my instructor told me, many slow learners become eventually the best pilots as they tend to be more carefull, more assessive and more cool head persons.
So don't worry and enjoy it the most you can. You won't regret it.