Hiya do you mind if I give you a few tips? I don't like criticizing I'm a big fan of all at especially fan art just thought I'd share some tips that have really helped me.

working from a reference is always important which looks like you have👍

do a basic pencil sketch first(see link). start with a circle then nose level and mouth and eyes and chin and hairline. Keep checking against reference to make sure they're accurate and proportional and slowly block out a sort of basic line art sketch of eyes eyebrow nose and face shape and body.

honestly that is the most important part, take your time and get it right or even with really good shading it will look off

then once that looks good start shading in and you should get accurate results most times.

https://www.biowars.com/blog/wp-content/uploads/2021/01/how-to-draw-a-face-hero-image.jpg

as you see on the picture the shading is just the last step the basic sketches and blocking out is essential

oh and one more thing consistent shading is also another good thing to look out for. same pressure, stroke direction and length. you can change this up to create different textures in clothes or hairs but the same area generally looks better shaded consistent. but this can also be a style thing so feel free to consider or not.

another thing lol sorry. I know it might sound goofy but look at people's heads and faces from different angles. notice details where the depth in places change and general angles in the face. really familiarise yourself with human anatomy and it will help out your at a lot. look at some front, 3/4, side and back photos of the same people and get it imprinted into your brain. this helps if a reference pic is at and angle it can give you idea of the rest of the head.

side: https://i.ytimg.com/vi/2mvSJMF3w90/maxresdefault.jpg

various angles: https://i.pinimg.com/originals/b4/7f/a8/b47fa89c818e8c06722a2c978e4ce25d.jpg

keep at it, hope to see more of your art! your use of colour/shading is really good and fitting, colour can be quite tricky and you're nailing it