Passing the driving test without a school instructor
It is very possible to pass the driving test without the help of a qualified instructor even on the first attempt, but to increase your chances of this happening, you need to go about preparing the proper way.
Many people think that there some driving test secrets which only a few people including the DSA examiners know about, and therefore the best you as a learner can do is to use an ADI to prepare for the practical car assessment. The Driving Standards Agency has publicly made available all the information that anyone who wants to take the test needs via its website and various publications which you can buy.One of the publications that anyone learning to drive without a driving instructor should use is The Official DSA Guide to Learning to Drive. This book written by the people who conducts the UK driving test contains all the information that the learner driver needs to pass because it tells you the standards required and with the help of your supervising driver you can practise these skills until you master them. As long as you abide by the advice given in the book and are confident you can do all that is required, then driving test nerves should not be an issue and you should pass with flying colours.
Driving School Instructors and the practical car test
If you are not a foriegn license holder, don't have or can't afford a car to learn to drive with family or friends, then the only option left for you is to use a DSA approved driving instructor (ADI) in your quest to passing the driving test.
On your first lesson, you should check your instructors registration badge to make sure they are operating legally, as you don't want to be wasting your money paying someone to teach you to drive when they aren't qualified even if they are offering you very cheap driving lessons.
As long as your instructor is fully registered and not illegal, you can fully rest in the assurance that you will be getting the right tuition and driving skills to get you to the DSA test standard, but it still doesn't hurt to buy the The Official DSA Guide to Learning to Drive book as you can read that when not having lessons just to supplement your knowledge.
If you have a car, and can also do some private practice, make sure that you drive according to the dsa standard taught by your instructor and not the advice of your family, friend, as this will guarantee a driving test pass if you continue to do things the right way and don't cut corners.