Some comments:
-I'll repeat what is said to a lot of people: you need more contrast. Your colors are way too close together.
-I'll also repeat what philipptr said about the black outlines. They work sometimes, but on this sprite they just make it flat.
-I assume the legs are unfinished? If not, they should be shaded...
-Your lightsource is inconsistent; the head is shaded both from the left and from the right. Your shading shows similarity to pillow shading in places, but not so much other places. Most of the body is shaded from the right; the head should probably join it.
-The forms are mostly clear, the exception to this being the head. This is probably due to its confused lightsource. Try to clear it up so that it is easily readable as whatever shape it's supposed to be.
Overall, good start. Welcome to Pixelation!