The practical driving test is conducted from driving test centres around the country.
I use the Guildford and Farnborough centres.
You will be expected to drive to a high standard to pass the test. The test lasts about 40 minutes. Examiners do not have a "quota" of passes. If you achieve the required standard, you will pass.
You will be asked if you want your instructor or a friend to sit in the back of the car whilst you take the test but they can not interfere in any way with the test either verbally or with signals.
During the test, you will be taken on a specific route which is designed to cover many different types of road. You will be allowed to make up to 15 driving (minor) faults. These include things such as an incorrect signal (quickly put right without any help from the examiner), a missed mirror check, stalling the engine or not making progress when necessary (hesitating). All this is on the condition that you and other road users stay safe at all times.
A single major fault means you will fail.
Major faults include things such as breaking the law, causing another road user to change speed or direction to avoid you, driving with a wheel on the kerb (eg during a manoeuvre), failing to react correctly to road signs (eg speed limits) or road (lane) markings.
There is currently a waiting time of about 8 to 10 weeks at both Guildford and Farnborough test centres. This means that I may suggest you apply for the test before you are completely ready for it.
Please remember: there are no guarantees that you will pass. It all depends on what you do on the day.