Greetings and welcome to Smogon!
You've definitely come to the right place.
The Smeargle's Studio section is the breeding ground for a plethora of versatile art galleries from all kinds of unique artists.
In addition to this, there's a notable sense of community, which means that people here are always willing to comment on your works in order to help you improve.
I'm unfortunately not an artist myself, so I can't give you much constructive criticism, but I can tell from my own experience that people exchange experiences and techniques on a daily basis.
If you're a Discord user, then you can join Smeargle's Studio's channel as well and partake in the live chat there.
Other than that I wish you a nice stay here and I hope that you find what were looking for.
Also don't feel disappointed if you don't improve right away. Being an artist is a never ending learning process.
Just remember Charles Horton Cooley's words: "An artist cannot fail; it is a success to be one."
Good luck!