You do not need long fingernails to play guitar. In fact, it's best to keep your fingernails short! As for the callouses, these may be unavoidable. If you would like to avoid them as much as possible, ask your guitar instructor about lowering the action of your guitar (the action is the distance between your strings and your frets) so that the frets are easier to press down on.
Learn how to transition to different chords. One way to become proficient quickly is to learn how to transition between the various chords quickly. These transition periods are often the hardest for beginners to play when they are starting off. The more you practice between switching to different chords, however, the better you'll get at doing it in songs. Practice switching between open chords like G, A, E, and C. 
The guitar is a remarkably hackable instrument for a million reasons that will be revealed to you as you spend more time with it. As you go along in your journey you’ll find a million shortcuts and fun ways to learn fast. I’ve rarely heard any of this stuff from guitar teaches, so beware, trust your instincts, and learn from people who can show you where you want to be.
I've seen so many guitar lessons where the instructor simply dives right in and begins teaching chords. Unfortunately, that assumes that the student's guitar is already in tune! Guitars are made out of wood, and wood reacts to our environment, be it hot, cold, dry or humid. As such, guitars frequently go out of tune, and they must be tuned to make them sound good. If you begin learning to play guitar on an out of tune guitar, it will not sound good to the ear no matter how hard you try, and as such, it will become discouraging pretty quickly.
A few years back, I dusted off the ol' Takamine I got in high school to try some 'music therapy' with my disabled son, who was recovering from a massive at-birth stroke. This reignited my long dormant passion to transform myself from a beach strummer to a 'real' musician; however, as a single mom, taking in-person lessons was financially difficult. Then I found Justinguitar! Flash forward to today; my son is almost fully recovered (YAY!), my guitar collection has grown significantly, and I'm starting to play gigs. None of this would have been possible without your guidance and generosity, Justin. Thank you for being part of the journey!
After you have selected a style and a teacher, you may want to keep some extra questions in mind for your first guitar lesson. An in person lesson can be very valuable, if you show up, and if you do the work that the instructor gives you for when you are not meeting. One of the greatest methods of improving is to consistently play. Play multiple times a week, get those practice repetitions in.
These beginner guitar lessons cover everything you need to know in order to get started playing the guitar. You'll learn the basics like how to hold the guitar, how to tune a guitar, and what all the parts of the guitar are called. Then you'll move on to learning essential guitar chords, strumming techniques, and how to put everything together to play your first song. These beginner guitar lessons are essential for anyone that has always wanted to play the guitar, but never knew where to start.