My parents thought me when I was 12 so I never even went to driver's ed. I had to wait till 18 to officially get my real license though because of some legal issues.
All I did was take the computer test at the DMV and the driving test. Never did driver's ed or anything like that.
If you are taking classes, you only need to do one session and practice at home, with your parents helping you out. You will learn all you need at driver's ed the first time around, if you pay attention. One session around where I live is only one week/5 days so that would be all you need.
It's fairly easy and something I was able to learn in just 15 minutes at 12 years old, so I am for certain you don't need any more classes. Driver's ed just give a full definition of what you need to learn and all the right and wrongs of driving.
The only tips I would give you is if an instructor tells you to do something, do it.
Keep your eyes on the road and use both hands on the steering wheel at all times when you are with an instructor. They subtracted a huge amount of points when I used one hand for the steering wheel.
Also, when you turn, make sure not to do a sharp turn but slowly turn to the left or right.
Have the radio/mp3 player OFF! This is a must.
Doing these will make your instructor love you. Just some past tips I'd give you. I will say this that I was able to learn how to drive manual/standard myself so if I could do that you should have a breeze in this, especially if you are the person that adapts fairly quickly.
How old are you if I mind ask you?