First you have to do a CBT before you can even go on the road.
As you are over 17, you will be able to ride up to a 125cc machine, although it must be restricted to 14.6 horsepower.
You can not take passengers, or go on motorways.
From here, you can do one of two tests, A1 and A (restricted)
A1 means you can ride up to a 125cc, again restricted to 14.6 horsepower....basically, you loose the L plates. Pointless
The A (restricted) is done on a 125cc bike, once passed you can ride on any bike, provided its limited to 33bhp.
After 2 years at 33bhp, you can ride any bike you want.
Once you are 21 - you can take a DAS (Direct Access)
You can take a test on a bike of at least 46.6bhp, and then ride anything you want.
If you do your A (restricted) test like above, and reach 21 before the 2 years is up, you can take an “Accelerated Access” course / test, which will quickly get you derestricted, and able to ride anything.
More to come.....