Nice work! I'd suggest giving your character a little more room to breathe in the composition currently; a nice trick is to get the head lined up with the top third to give the focal point room the breathe. I'd also be careful with your values and contrast, currently it's very easy to lose your character in the background so maybe try and separate your values a little more.
If you want some reading material to really help you with composition definitely check out Framed Ink by Marcos Mateu-Mestre. Incredible book on compositional theory and storytelling!