WOAH!!! This is amazing for a first try!
I will say the black outlines are a tiny bit to thick, but still it is very very good! You did very good on the leg shading and the eyes, you added light in the perfect places :3
the cutie mark looks really good as well.
The mane and tail looks good, I like the dark blue streak through the tail..
The back leg looks good :3
I really don't know what to say it's so good
You did a very amazing job for a first try! I hope you draw more.
Anyhowl, have a good weekend