It is very important that your car headlights are pointing in the same direction. Usually people let the adjustment of their car headlights for their mechanics to do, but it is something they can easily do themselves. Mechanics usually use a special adjuster which makes the car headlights look perfectly adjusted and looking at the exact same direction, but doing it your self you can achieve a very satisfactory result as well.
If you wish to adjust your car headlights, the first thing you should do is make sure of parking your car on a leveled surface and pointing to a wall or garage door. If the car is unleveled, then you will end up adjusting the headlights unevenly and it might cause you more trouble than before you had done it.
Then, you should look for the adjusting screws which usually are two, a horizontal and a vertical one. This way, you will be able to adjust them vertically as well as horizontally depending on which direction they are unadjusted and according to the leveling you are looking for.
Once you have located the adjusting screws, you should turn the headlights on. With the headlights on, and since you have parked the car pointing to a vertical surface, then you can check the leveling of the lights according to how they are reflected in this surface. The lights should look equally and pointing evenly, if they do not then you should adjust them. Ideally, you should find the exact point in which the headlights are pointing to the front but a little downwards in order to avoid blinding other drivers at the same time than following the proper safety and headlight related rules.
You should use a screwdriver which properly fits the headlights screws and adjust them until you reach an even leveling. You should go checking how the lights reflected against the vertical surface look in order to make sure you are doing it the right way and avoid wasting time and effort. You should do this during night time or in the dark when you can check the lights reflect properly and accurately.