Have a look at the video below of Ayaz taking his mock driving test. He's had 43 hours of driving lessons and has a driving test tomorrow. He wants to use this mock test as a practise run for the real thing and learn from any mistakes.
Bear in mind that the examiner on your driving test might not think that every mistake you make is big enough for a fault.
The benefit of taking a mock driving test is to find out how ready you are to drive on your own and to experience driving test conditions. Learn from any mistakes and go on to pass the real driving test and be a safe driver.