Looks pretty good as a start.
As mentioned, don't use black for shadows unless you have a very dark blue or gray (to achieve an overall black) base color.
Try going for a mid tone for the base color of your clothing. Use a color wheel and find opposite colors to get your shadows by adding that to the base. Use a lighter shade for highlights, or again, refer to teh color wheel.
Don't get trapped in the idea of using a wash for your shadows. develop a skill set right away to lay the colors in and feather the edges by blending (oils) of very thinned appliations of he highllight and shadow colors (acrylics). See the tutorial under Model Colors at
Vallejo's site.
As to your figure specifically. You seem to have missed shadows in many of the folds. Each should get an application of the deepest shadow on the under side of the fold. Likewise, lay on more highlights the same way as the shadows but on the upwards facing part of the folds and on the upper thighs and shoulders.
The dirt on the boots looks really good, but I'd break the rules I just gave you and put a wash of oils or inks to outline the closures then drybrush the raised detail.
The face, what I can see of it, looks decent, good flesh tone, some shading, but try punching that up a bit. Lay in some frown lines along the edge of the nose, some mode shadows on the hollow of the cheeks, the some increasingly light highlights along the upper part of the cheeks, the ridge of the nose, across the top of the lips, on the chin and jawline. Try to get a slightly pinker flesh color for the lips themselves...GW or Citadel has a "Tanned Flesh" that works really well on male lips.
Put a shadow line above and below the goggle strap then a highlight at the top of the strap. Do the same with the collar, cuff straps, pockets and epaulettes.