I don’t agree with a lot of what the other poster said but I will vouch for chord charts which are easy to use.

Most of them look like this:

        Am   C        D           F
  There is a house in New Orleans
       Am        C      E     E
  They call the "Rising Sun"

And all they’re telling you is which chords to play when.

The ones with 6 strings are just giving you a reference for the chords if you don’t know how to play them.

I play guitar for a church and we use chord charts for all our music.

> Haven't heard the term, and I'm not from a western country

Understood. Indian music uses Sa-Re-Ga-Ma-Pa-Dha-Ni, but it means the same thing. The key to understanding that system is that Mi-Fa and Ti-Do (Ga-Ma, Ni-Sa) are half-step intervals (consecutive frets on the guitar), every other interval is whole step (skip a fret). Historical Western solmization doesn't even use Ti (the indian Ni), so everything always revolves around that single Mi-Fa and there are fewer syllables to remember - "mutations" where the syllables rotate in meaning are used instead. (If you search for videos talking about "Italian solfeggio" there's an episode of the Nikhil Hogan podcast talking about why these older systems actually make musical sense, despite seemingly being more complex. This system was what professionally educated musicians learned back in the 18th century.)

So if you know what solfège note you're playing, that tells you immediately how nearby places on the guitar fretboard will relate to the scale. Notes on other guitar strings are also related musically via interval relationships that depend on the tuning, and can be derived quite easily or committed to memory.

BTW, I think anyone who's interested in music to any extent should learn to read standard notation, even if they only play guitar. It's the language that literate discourse about music has relied on for hundreds of years, at least in the West. And the basics are quite simple, being founded on the diatonic scale just like solfège.

Ahhhh... This brings back sweet memories of a music theory/practical harp, grad student that I used to date. She was always able to instantly play any pop songs I requested as harp arrangements; watching someone truly play an instrument as if from feeling is magical. But I really feel like guitar playing is a different beast all together. There is no other instrument with the amount of "players" that the guitar has, ranging from low skill to high. But in general, I've watched multiple people teach themself up to a level where they can go no further on their own. Then you take your learning on a specific path. Classical training if you want to end up as a studio musician or composer; non classical if you want to be the guitarist in a moderately successful hardcore band. (Does playing Warp Tour make you a success?) That's what happened to the three best guitarists I've known, and I suppose my point is this: GP can, and should, skip the not-so-fun stuff for the time being. Guitar is unlike other mainstream instruments, and simply playing is the best way to improve (even if it means developing bad habit)

But why is it that musical awareness of what you're actually playing on the instrument has to be the "not so fun" part, compared to just mechanically following some existing tab? I would dispute that point. I would also dispute the notion that "the guitar is too unlike" other instrument families and standard learning methods cannot possibly be applied to it.

But how do I know what solfege note I'm playing with a single note, since it's all relative?

From what I can think of, I can either need to know the song's key (and will have to rely on the internet for the same because I don't have perfect pitch?), or I'd need to have at least 3 or 4 notes to figure out what major scale it might possibly be? (And still it isn't enough I might be wrong).

What am I missing?

When you learn a song by ear, you'll know how each note of it relates to the key (which is the "home" note, and the one that the song might end with). You also know where the half-steps are in the scale. These are basically enough to know your solfège/solmization syllables for that song. Note names and perfect pitch are irrelevant because most of the time you'll be playing fretted notes, so just shifting your hand location on the fretboard lets you play different pitches - the actual "note" pitch is arbitrary. Notes played unfretted (that you can't just move around) are rarer, so you can always think of them as falling outside the pattern and learn them as such.