Don’t listen to people who say learning how to read music is a waste of time.
This is where it gets a bit controversial, because so many guitar players have never learned any formal music theory, have never bothered learning to read traditional notation, and see no practical application of these things to their guitar playing.
But the advantages of learning a bit of music theory are pretty obvious once you get over the original hump. And getting over that hump is actually quite easy.
We’re not talking here about learning complicated stuff. At the beginning you just want to learn a few basics so you can use them for learning purposes: scales, exercises and simple melodies.
There is no serious downside, and the “upside” is that you’ll discover new musical opportunities you didn’t know existed.