Hi mate, more than likely he would've asked if you were natural or goofy so that he could pick a board that already had the bindings fixed the right way
Don't stress too much about your second day not being so good, I don't think anyones second day was all that great. (Not even Terje!)
It's very important for your boots to have an equal amount of overhang on both the toe and heelside, because if there's more overhang on your toeside it will be difficult to initiate a heelside turn (and vice versa).
Take your board back to the rental mob and ask them if they wouldn't mind centering your boots for you (or do it yourself).
Keep at it mate, it'll all connect together sooner or later. It's already been mentioned, but lessons would be a great idea too
Short video explaining centering bindings: http://www.youtube.com/watch?v=NK7X2...HypRdZlk7lzJ4c