I find it baffling that from what I've heard/seen on TV in some states you can drive when you're 15 years old, and that they teach "drivers ed" as part of the school curriculum - is that right?
Where I live... You can get a learner's permit at 15 after you've taken a theory test. You then log at least 35 hours of driving with a qualified driver over 20, including day and night driving, and if you are under 18 you also take a 35-hour driver's education course (not provided through school).
Once you've done that and you have hit age 16 you can take another test and get a permit to drive unaccompanied.
You cannot carry passengers under 20 until you are over 18, if you're under 21 you cannot drive from midnight to 5 am and you cannot use a cell phone while driving. If you have any alcohol at all in your system you will lose your license.
TBH I think it's a pretty sensible system and not particularly baffling...