As someone who has been playing for 30 years, the best advice I can give you is that it's way more important to play it correctly than it is to play it fast. You're naturally going to want to rush and cut corners to try and make the thing sound like the thing as quickly as possible, but it's in your best interest to fight that urge, slow down, and focus on accuracy.
The vast majority of what you're doing when you're learning guitar (or any other instrument) is programming muscle memory. That only happens through repetition, and it's a very garbage in/garbage out process. If what you repeat the most is clean accurate movement and good technique, then that's what's going to become automatic. If what you repeat the most is sloppy, rushed, and full of mistakes, then that's what's going to become automatic.
This isn't to say that you're not allowed to make mistakes. You're going to make tons, and you don't really need to beat yourself up about it. Just notice when it's happening and then slow down and really focus on breaking down the movements and playing it cleanly and correctly. Once you can do it perfectly playing slow, then you can start speeding up again. I don't know if you've ever heard the saying, "slow is smooth and smooth is fast," or, "you have to slow down to speed up," but there's nowhere it's more true than in guitar playing. A huge portion of what makes up speed on guitar isn't just physically moving faster, it's accuracy and economy of movement.
Other than that, spend time practicing with a metronome. There are some good free ones you can download on your phone. It will help a lot in developing an accurate sense of rhythm, but just as importantly it will help train you to follow external cues while playing. This will be massively helpful later on when you're jamming with other musicians.
Also, as much as possible, keep your guitar in tune, and tuned to a consistent pitch. Having that consistency will help develop your ear for recognizing pitch, and will make trying to learn songs by ear a lot easier later on.
I've been playing for 13 years, and I still struggle with lead parts because I wanted to play fast too soon... Do you think it's too late to course correct? Specifically, I suck at keeping track of where my pick is when switching strings, and complicated parts where I switch between frets and strings fast are just 🙃🙃
I kill it on the rhythm section tho, just for the record. Because I had the exact opposite approach there. And it's like night and day. I can feel how I can do all the little subtle things rhythmically the way I want to do on lead, but instead my lead sounds clumsy a lot of the time.
I don't think it's ever too late. Obviously it can be difficult to untrain bad habits, but it's really just about sitting down and consistently doing the work. Forcing yourself to slow down can feel super tedious a lot of the time, sometimes you need to go like agonizingly slow for longer than you really want to in order to crack the part you're working on, but it 100% pays off if you do it. And a lot of time you'll eventually have to go back and do it over again because certain sections got sloppy over time. I still have to do it even after 30 years of playing. I don't think it ever really ends.
Been playing for 30+ as well, heed this advice. To this day I still have shitty technique that I've had to learn to compensate for because I wanted to "play good fast".
Thank you for this write up. My work uses "slow is smooth and smooth is fast" so I most certainly know what you mean.
I've realized I need to use more formal routes to make sure I practice the "correct" way. I had intended for lessons much later but I think I am going to speed up that timeline a bit.