This is your first model? If so, you're doing a great job. Maya is a hard software to learn, specially if you're doing this by yourself. But I'm sure in the next challenges you'll doing even better. Keep rocking, man.
Since the geometry of your char looks a little confuse, here goes another approach for cleaning it:
Take your original model...
...and make it live (Modify>Make live)
Using Polygon>Create Polygon tool, make a first poly over the original. The tool will snap on original's vertices.
Using Polygon>Append to polygon tool, make new polys until complete a ring. Don't forget, the default hotkey to reuse a tool in Maya is "Y".
Keep doing new polys until you finish your geometry (I didn't finish here, but you know what I mean)
And it's over. You have a model looking as your original but with clean geometry.
If possible, try to make a sketch of your model and the basic geometry it must have.
If you couldn't use this in your current model, keep this method for the next challenges. Good luck with your demon!