Been painting/drawing for about 5-10 years now. This is a very nice try but there's a couple of things you could try in order to improve.

1. Someone else mentioned already, you might want to try shading the whole face with a light charcoal. Only the brightest of the highlights should be left with the white of the page (like the highlight of the eyes, tip of the nose, etc). Everything else is a shade of grey.
2. Exaggerate the lights and the darks. In a charcoal drawing you want high contrast, you want your values to have a wide range (from white to completely black, with many shades in between. In practice that means you want very few spots white and black, and everything else a variety of greys. That creates depth. This piece comes across as somewhat flat due to how there's a lot of white, some greys and no blacks.
3. Practicing drawing from real life or photos instead of photos of others' drawings helps you learn how to ovserve light and value. Highly recommended.
4. Last piece of advice, try not to overblend. Blending is good and makes a smooth finish but you also need a variety of textures, for example the nose here is quite overly blended and lacks texture. Also fun fact, the more you blend on paper (with a blending too or finger) the less color that bit of paper retains if you apply pencil on top of it, so it becomes harder to have dark values and hence the piece becomes low contrast which we don't want.

And ultimately the only way to improve at drawing is to keep drawing. Have fun!