Everything seems way too light, that's either my monitor or the scanner, I quickly darkened it on PS anyways. But basically to reiterate on Cal's point you need to use a wider range of values, which I know is a real pain with just pencils shading large spaces. You could try a few quick value studies with other mediums (charcoal, markers, digital were my go-to) to get a good range, and just do quick test sketches. But still, that's definitely a great first portrait, better than my first for sure, and it's always good to push the parts you're weaker in.