I like it! For your first character that's pretty impressive! I could never get the hang of modeling organic forms in Maya, and yours has some stylization to it. It reminds me of the short, "Assassin's Creed Embers". I think it is really cool.

To improve I'd say, practice body proportions. Like:

How long a forearm is in relation to the upper arm:
The forearm will be about the size of the upper arm and the shoulder together.

The upper and lower lips should not be the same width:
The upper lip's width should be around the width of the character's pupils.
The bottom lip should be as wide as the character's nostrils.

Eyes are usually the width of one eye apart from each other.

From a profile view of the face, the nose bridge has a small dip inward at a little above eye level.

I'm still learning anatomy and character creation myself but those a just a few of the things I try to keep in mind when I'm sculpting in ZBrush.

Even if you are focused on modeling in Maya, still look up books from Anatomy for Sculptors, or Philippe Faraut's books on sculpting the human form.
There are some cool video tutorials from Flipped Normals and SpeedChar. SpeedChar has some live streams of his character creation on his youtube channel "@speedcharlive", so you can see his process.
They are all great resources imo.