The most difficult task that a beginning guitarist faces is tuning the instrument. As it takes time to develop a sense of pitch, I recommend that you use an electronic tuner at first. If you don’t have one, go get one. It is impossible to learn to play on an out of tune guitar.
You can pick up an electronic tuner for about 2k or a pipe one at sh500, and it will pay for itself before the end of this first lesson. Make sure that the sales person shows you how to use it, and pay attention to what they tell you.
If the instructions don’t make sense to you, DO NOT leave the store until you understand EXACTLY how to use the tuner. If the sales person acts like they have something better to do than educate you on how to tune the guitar,go buy a tuner somewhere else. Playing in tune is THAT important!