If you're playing guitar on your own terms, or any instrument really, know that the number one rule is:
That's it. That's how you play guitar well.
I hope that doesn't sound reductive, because that's coming from a really genuine place.
Okay. So maybe you're not so sure what exactly sounds good to you just yet. That's ok too. Maybe then, you should try to identify your goals. (These can change at any times so don't feel super committed to these.) Do you want to write original music? Do you want to play covers of your favorite songs? Do you want to have unstructured jam sessions with other musicians? All of these are valid, or maybe you want none of those things. But it's important to know why you're wanting to learn guitar.
Regardless, learning things always works best when you're having fun and it doesn't feel like work, and my top recommendation for total newbies will be to try to learn some of your favorite (easy) songs. I say "easy" because difficulty is relative but if we're being honest with ourselves, we're probably not going to master Jimmy Paige guitar solos in the first few months. Don't know what song to learn? I'm partial to Bobby by Alex G as a good "easy" song, but i highly recommend you pick one for yourself.
So how then, do we learn our favorite (easy) songs, now that we know that's a thing we should probably try?
Well, first let's get acquainted with the fretboard.
don't mind me, i'm just putting filler text here to create space. lorem ipsum something something, ok bye.