Fingering positions on a guitar is easy. The strings are, from
top to bottom bottom to top, E, B, G, D, A, and E. Each fret, starting with the first, is a semitone up from the open string, and the semitones are C, C#, D, D#, E, F, F#, G, G#, A, A#, and B.
If a chord is played properly, sending it's sound into a tuner will produce the chord's name, as the collective frequency will be the same as the raw note.. or something like that. I can play an E chord and my tuner says it's an E note, so that's cool.
I don't even know what a ligature is, so you're screwed there.