Anything under 18 is scary in my opinion. Even if you can't have passengers, some kids still do, and their parents don't raise any eyebrows if they're out with the car 'by themselves'.
In most states of Australia you can get a learner's permit at 16, which enables you to drive so long as there is a fully licensed driver in the passenger seat next to you. This is just a written test, as it's assumed you've had no driving experience. You also have to display what we call 'L' plates on the car. These are yellow squares that must be put on the front and back (windshield or bumper bar) so that other drivers know that you are just learning. They're great, because people know to give you extra space and to be extra careful - although there are drivers out there who don't care I think they're great, but both when I was a learner myself and now being a fully licensed driver.
When you turn 18 you can go for your Probotionary License. You must have held a learner's permit for at least 6 months prior to going for this licence, and you have to pass a written and practical driving test. Your probotionary licence lasts 3 years, and during that time you must have a zero blood alcohol content and cannot drive super high powered vehicles (but then, what normal 18 year old has a ferrari?). You also have to display 'P' plates in the same way as L plates. These ones are red and white. There's no restrictions on the time of day you can drive or how many passengers can be in your car licenced or not (beyond the obvious seatbelt requirement).
I believe there is one state in Australia that does this differently (maybe the Northern Territory?) and lets kids drive at 17... but I'm not certain about that.