I'm making a big deal about this because it's a big deal. Please understand this: A good setup on your guitar is a make-or-break priority, especially for beginners. You can power through with a bad setup for a while, and you'll hear lots of hero stories about virtuoso players who learned to play on a cigar box guitar with fishing-wire strings. But in real life, every 11 minutes a beginner quits because their perfectly good guitar isn't set up properly. Those beginners probably don't know that's why they quit, but it is. I'm a strong player, and I can't play well on any guitar with a bad setup, so chances are neither can you.
What is the biggest culpret of bad guitar setups? Anyone know? It's the string slots in the nut of the guitar. That's the 'zero fret'** at the base of the headstock. The depth of those grooves determines the string height across the whole neck. Many experienced players don't understand this - 75% of the 'personality' of your guitar, and every guitar has a 'personality' good or bad, is simply whether the string slots are cut correctly.
Experienced players spend hours adjusting the bridge and shimming the neck, without success, when the real problem is the string slots. I've done this myself, before I became enlightened. But it gets worse. Those same experienced players reason that the solution is to pay lots more money for a better guitar, when they can have the guitar of their dreams by spending $100 more on the guitar they already own. It's crazy.
But I just spent $300 on a guitar, now I've got to find a "guitar tech" and spend another $100 ?!?!
When you buy a new guitar, you should factor in $100 if necessary to get a once-in-a-lifetime adjustment of the string slots in the nut. Once you get that done properly, you wont have to mess with it again. Until that adjustment is done properly, you don't have a fully-playable instrument.
It's an after-market adjustment that you as the consumer have to make. It's a high-tolerance adjustment that requires special tools and precise measurements. You don't want to mess it up, or you have to replace the nut, which is difficult. It's an adjustment you wont see, unless you have a trained eye. But your hands will know the difference the second your fingers touch the neck.
It's a pleasure to give a guitar back to a student after a setup. They're amazed at the difference. They can't believe it's the same guitar.
When a beginner gets a new setup, they suddenly realize playing is possible after all. For the first time, their hands tell them, "I can." I've seen that flash of realization several times. Sometimes they're eager to get rid of me so they can try out their 'new' guitar for themselves, without me telling them what to do. That's 'curiosity,' and it means that student is going to stick around for a while.
Beginners, and more tragically, beginners' parents don't understand this stuff at all. That's understandable, it's complicated. Most experienced guitarists don't understand it.
Read: Make Your Guitar Easier To Play
** Some guitars have an actual 'zero fret,' an extra fret just in front of the nut. On most guitars, the nut functions as the 'zero fret.'