Now there is no reason to feel bad that you did not pass the test. You simply did not have enough information and you are not the only one. Many people fail driving tests. It is part of learning how to do things right. The good thing is that you can retake the test as many times as you like.
Your car is an expensive asset which means it comes with the risk of theft. Locking the car door is not enough. You will have to take other measures to ensure that this precious asset is not stolen. There are different security companies that you can approach for car security solutions.