Just remember that your instruction allows for the fact that you are not going to be full bottle on this from day one - it can be daunting to think "how am I supposed to know ALL this stuff???"
Each time you go up, around and down, you will be consolidating a little more of what you need to know.
So I wouldn't stress too much about what you don't know, just concentrate on the stuff you do know, and everything else will fall into place over time (as long as you pay attention).
One day (and chances are it will be a surprise to you
) the instructor will hop out, you'll go solo, and you'll realise that all the work you've put in is starting to pay off.
Then you'll realise there's a stack more to learn. But that will all fall into place too if you work hard.
Good luck, learn from your mistakes, and enjoy it all.
Also, don't neglect the theory. Get ahead of your BAK stuff.