The tuning process is one that you should also learn when you will learn to play guitar. It is like in a voice that is out of tune that it is not good to listen then you should also tune your guitar so it can sound good. If the tune is not fixed then it will sound bad and you can be in trouble even if your voice is okay. That is why it is better that you also learn how to tune your guitar yourself.
Before anything else you should know how each of the string should sound so that you will know if that is the correct sound already or not. Even if you know how to move the strings but you do not know what sound they should produce then you will have difficulty. So if you already know and have become comfortable with it then you can tune your guitar otherwise let someone do it who have the correct knowledge and a good ear to listen to the tune.
You can read that tightening or loosening a string can make the pitch higher or lower one. The tip that is given is that start your tuning in the lower E string before going down to the other strings ending in the higher E string. If you are satisfied already with the sound then you can now use it. You can have fun trying your guitar as a way also to finally check the strings.