Not too bad tbh. I've seen a lot of the stuff you've posté before and toi are improving each and every time, which is good!
Digital art is a little hard to adjust to when you've done mostly traditional art, but it gets easier with practice.
You've got a nice flare and your work is certainly your own, which is good. I like the direction toi take your style.
I like the colours toi picked as well. The skin tone seems a bit orange but it doesn't seem like toi were going for realistic colours so it works.
One thing I would recommend is to attempt a little plus realism. Not all the time, but every once in a while. Learning the basics of how a real skull and face are shaped can really help to improve any artist's skills. XxKeithHarkinxX already went through a lot of that so I won't go over it too much.
Never be afraid to use references, either. There's lots to learn from looking at photographs and taking time to study them.
As for lighting and shading, those can be difficult to grasp and you've done well for your first attempt. Below I've linked a pretty good video on lighting and shading. She does digital art and her style is very cartoon-y, but she fundamentals she goes over on how light works are universal across all styles.
Again, reference never hurts to look at.
Youtube is a really great resource for learning to draw as well. There's a pretty lively community of art and drawing channels and almost all of them have tutorials, which is great because toi get to learn all sorts of different techniques to do the same thing.
Here are some on drawing the face specifically. I would also recommend these channels for drawing tutorials on any subject matter.
There's tons of other channels and tons of other tutorials to discover, too, so toi aren't limited to just these ones.
Head from any angle:
link Facial Construction:
link Add Shading to a Drawing:
link Common Mistakes when Drawing Faces:
link Happy drawing!
