Sorry for the late reply, but I would just advise to go for it! You can keep telling yourself you're not good enough yet but that way you'll probably keep telling yourself that month after month (like I did) and it never gets done. Your work doesn't have to be pixel-perfect imo, only other pixel artists care about that. :^) Clients usually don't look at every individual pixel like we tend to do (this is not meant as an excuse to hand out sloppy work).
It's good to have a high quality standard, but don't lose yourself in perfectionism. I still tend to do this though and waste a whole week on a piece that could've been finished in a day...

Regarding commissions, I luckily had a few friends who wanted to kickstart my journey, but aside from that I just post stuff on reddit/twitter/pixeljoint forum and link to my website where possible. Make some stuff for people with an audience, and/or reach out to them, and you might get a response or even an order from them. You do need some luck to reach the right people at the right time, but if you don't post anything you'll never reach them anyway. Think of that Gretzky quote, "you miss 100% of the shots you don't take". ;)

TL;DR Go for it!

Ay, I gotta start commissions too. Huh, if you don't mind me asking you here (and if I can ask), how are you handling commissions?
I would do a website, but is it bad that I don't want to make it yet until I figure out how to make my posts pixel perfect, or should it not matter?
 

Thank you! I hope so too, I'm already getting some paid commissions and gigs so the future is hopeful. :)

Nice work! Hope you get to keep practicing pixel art