Ahh. I'd first off like to say that this is a very good first try and i'll commend you for your efforts. Theres a lot to unpack here-
So in terms of entries and being hired as an artist, unfortunately with you being a COPPA member, it would be difficult to communicate through the means of CS or otherwise as COPPA members aren't allowed on our Discord and do not have access to CS pms. So even if you made 3+ entries I would have to wait until you're no longer COPPA to hire you. You can of course continue to make entries while you're still COPPA that is 100% totally fine and i encourage that! I just want to make it clear that due to issues with communication the hiring process would make things difficult.
With that out of the way heres a critique and some tips for your entry.
The linework is fine and certainly remind me of the breed (though please make sure to define the ears a tad more to make them less solid triangles), but the markings and coat colors need some work. Pembroke Welsh Corgis are generally Fawn, a dilute of red, but it usually comes with a more tan color with some darker and lighter bits on the base. Theres a distinction between the lighter parts of the fawn coat and the actual white markings they have. The white they have is called Irish White, which is completely opaque (solid).
The image below better shows what I'm trying to explain.

The base coat (the Fawn) is less saturated and has various other shades of red/brown in the coat. The lighter bits that aren't quite white are part of the fawn base.
The white (the Irish) is more solid, having a lot less blending and more sharp lines that show where the white actually reaches. Irish white reaches the upper part of the front legs and at the least the toes of the back, as is standard for the coat, and connect the neck's white with the face's white.
The nose and eyes are accurate and don't need changing, but I'd suggest practicing more and absolutely using various references.
You're on a good path and just need a bit of practice!
Coat- Fawn with Irish White