Your individuality is your currency, so definitely stay cautious of any critiques that affect your voice and what you feel like painting. That said, you know that feeling of having the image in your head, but when you hit the paper (or digital canvas) it doesn't quite come out as good? All that is is lack of skill set. Lack of tools. You wanna corner your visions and print them out from your brain, you gonna need to up your fundamentals. It's a boring grind at first, but those effortless quantum leaps afterwards are well worth it.
Drawing is, effectively,about understanding shapes, so pick up Michael Hampton's book "Figure Drawing, Design & Invention", it's the GOAT anatomy book. Breaks the body down in the most simplest forms possible. I've redrawn it cover to cover multiple times and every time I pick up something new. Then there's Andrew Loomis books -
https://www.alexhays.com/loomis/ all available here for free. The Head & Hands one is the one I started with, personally. Excellent artist & teacher. From there on start learning about compositions (shit like rule of 3rds). If you gonna fuck with colors, you'll need to learn color theory. I recommend this playlist:
It's a severely underrated tutorial. Extremely bare bones and straight to the point.
Keep making your personal pieces, but upgrade yourself. I'm not saying to follow rules, I see these as tools. You wanna fish - get a boat... that kind of thing. I draw weird shit, but I've studied the standard way as well and my weird shit now looks much cooler than the meandering weird shit I drew before. And the stuff you wanna learn the least is most likely the stuff you should tackle first. But remember that intensity beats extensity, so just start somewhere and claim little victories a long the way. Also, if you wanna mess around and try and bamboozle people with symbols and stuff - I recommend you go way back and study paganism as well as Prisoner's Cinema -
https://en.wikipedia.org/wiki/Prisoner's_cinema A lot of these symbols like the Celtic cross, star of David, swastika - they have a much richer meaning and history than you can possibly imagine.
Lastly, 2 things - when you're learning this shit, try and think of it as a musical instrument. Like you're learning notes. In music, playing a guitar, when you fuck up - your fuck up vanishes instantly, but in art - that piece of shit you drew is right there haunting you. So don't think about it, don't look back. Just jam it out and move forward. And, dude, these quantum leaps in skill that you're in store... this probably won't make any sense, but here's the best way I can describe it:
You're a beginner, you have 1 point worth of skill. You look around and you see a great artist who's at 2000 points. You wanna be that good... Then you really push yourself - for 3 months you draw like a mad man... you're focused, you're on it and 3 months later you're at... 2 points. What? "2 FUCKING POINTS?! After 4 months?!" - Yes! "Does this mean I'm gonna need thousands of months to become great?" - No! These leaps in skill work like 1,2,4,8,16,32,64,128, 256 and so on. It's a weird growth and extremely deceptive. And the more you learn, the more the Devil will be in the details.
Yeah and... not to bum you out - this shit takes so much fucking time to get good at. Where you think you'll be in 2 years, you'll probably get there in 8 or 10. That's if you're above average in focus. And if you wanna do it professionally - you gonna get you shit pushed in bad at the start. Bad vision, carpal tunnel, shot to shit back, bad neck, spider veins, staring at a shiny screen all day making use of your phone, watching TV & playing video games an extra misery you'll consider avoiding, then there's weird working hours (if you don't get to work in a studio, but even then it can get weird), people who don't understand art telling you how to do things better, bizarre social life and relationships... I've done art and grueling construction work for a living - construction was mentally way easier. And you get to interact with humans instead of waiting on yourself to print out an image that you've been staring at hours on end.
Anyways, good luck, bro.
P.S. Here are some art channel recommendations to bathe yourself in:
https://www.youtube.com/user/novacolonyshow/videos
https://www.youtube.com/user/architectus777/videos
https://www.youtube.com/user/marcobucci/videos
https://www.youtube.com/user/reiqws/videos
https://www.youtube.com/user/FZDSCHOOL/videos