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.
Justin Sandercoe has thought long and hard about how to teach people to play the guitar, and how to do this over the internet. He has come up with a well-designed series of courses that will take you from nowhere to proficiency. I tried to learn how to play years ago, using books, and got nowhere. I've been using Justin's site for just over a year and I feel I've made real progress. What's more, Justin offers his lessons for free - a boon for any young player who has the urge to play, but whose pockets are empty. I've seen and used other sites for learners: none of them offer as clearly marked a road as Justin does.
After teaching guitar and music theory to thousands of students over past three decades, I thought that I had basically 'seen it all' when it comes to guitar instruction. Then I discovered Justin’s website, and man was I impressed! Justin’s caring spirit, attention to detail, vast knowledge base, and especially his lucid, laidback and nurturing style, allow students to fall in love with the learning process. You see, it’s not enough to simply find out how to play a few cool licks or chords. A truly great teacher will make you fall in love with the process of discovery so that you can unlock the best within you. Justin is one of these great teachers, and I highly recommend justinguitar.com to anyone who wants to tap into their best selves.
Open up audio for the riff and follow the tabs. Open the song that you're covering in another window on your internet browser. Play through the song and trace the chords and notes with the tab that you looked up. Try to follow the numbers on the tab with the notes that are being played in the song. Try to get an understanding for which chords the artist is playing before trying to duplicating it.
When you play the right note or chord, you will hear it. It will be a pleasant sound, it will be clear and won't have any blocked string sounds (unless it needs to, but you'll get to that later). To play a note or chord correctly, you have to get your fingers in the right position and press as hard as you can on the frets; it will become a habit if you practice enough.
Intermediate Guitar Class - Open to all ages, from age three to one-hundred sixty-three, but an audition or permission from the instructor is required. This class is intended to be challenging. Topics covered may include movable bar chords, song forms, repertoire development, fretboard mapping, improvisation, and other advanced techniques. New classes start every month and may be repeated as often as you like. Cost is $85 per month (4 hours).