Well, for starters. The parts of the guitar (image 2); starting from the top: there is the headstock, or head; the neck or arm, or fretboard; the frets; the body; the mouth, or sound hole; and the bridge. Also the notes and numbers of each string, in standard tuning. Counting from below, of the sharpest of all, is string 1, and is E; the next one is 2, and it is B; follows 3, and is G; follows 4, and is D; follows 5, and is A; follows the last one, 6, and is E, but more bass-sounding, an octave further back (I will inquire about that later). | Now, a little bit of theory. I hope you already know, about the notes or musical sounds. What it is: Do, Re, Mi, Fa, Sol, La, Si, or maybe as I think you know them, A, B, C, D, E, F, G, being synonyms: A→La, B→Si, C→Do, E→Mi, D→Re, F→Fa, G→Sol, and these when they end, start again, but more bass-sounding, in a lower note; or more acute, in a higher note, depending on whether you ascended or descended in the order. | Almost all songs or pieces of music are made up of these notes; So, I would recommend that you learn or play the chords of these notes in their major mode, which are the most common, and the easiest ones (image 1). I'm making you a spoiler: the ways in which you place the fingers, of these chords, are repeated throughout the fretboard, and it has to do with theory, you see, A, B, C, D, E, F, G, (almost) of these notes, in between, have more notes, which are known as their versions: diesis, or sharp (#); and bemol, or flat (b), depending on whether you are reading upwards (read A, A#, B), or if you are reading downwards (reading B, Bb, A). that is, for example, A# is equal to Bb (they are actually different notes, but it is accepted in music that these two notes are equal, so as not to confuse). Now, it is known as intervals in the way of counting distances between notes, and its distance measurement is in tones, and the next way is known as the diatonic scale (image 3). The diatonic scale counts intervals as follows: the distance between A and B is one tone, but the distance between A and A# is 1/2 tone, ah~, ingenious right? So when you read A and then B, you're actually skipping one note, A#. Not all notes have 1/2 tones, such as the range of D and B, and, E and F. So, back with the chords; if you make any chord, and you run it forward (and add a bar, if you need it), you would be making that chord, but in its sharp version (#) if that chord is not E or B; And if instead of going forward, you go backwards (and also, you add a bar if you need it), you would be making that chord in its flat (b) version. Doing this once again would result in the chord that follows it, being ascending or descending from the scale A, B, C, D, E, F, G. All the fretboard has chords, you can learn which are the bar chords of the most famous positions such as: 5 fret, 7 fret, or 12 fret. . .
That's all I can think of right now. If you get bored from de major tones, I recomend you to take a practice of the «armonical circles of the guitar» (I will upload the chords in another post), they have many chords and variations, such as, majors, minors, and sevenths? (I don't know how it's called in english), so you can learn them, and be familiarized with them. If you have doubts you can ask me. And sorry for the delay.