Tune a classical guitar can be tricky for beginners. For this reason, the purchase of an electronic tuner will save you unnecessary frustration. Train yourself also to tune by ear. Once your guitar is quite in tune, try to make the corrections utlime just hearing the notes in the first video, then check with the tuner if you have done well. If you do not want to buy a tuner, you can go to the website suggested later, where you find one free! The second video shows the method for relative tuning to the classical guitar, a bit tricky for beginners, but very educational for the ear.