Ok so there's not a lot here to critique besides the character so that is what I will do.
There is a lot you can work on. Your linework is not confident, these are pretty squiggly. A solution could be to use a stabilizer option or maybe use a better program (Medibang Paint Pro is solid and it is free last time I checked).
By far the biggest offender I need to address is how you construct faces. Right now it looks like you draw everything on a single layer and draw the hair before tackling the head shape and face. Which is not a method I recommend using. If you draw a head, you should plan out what you want and how you want to get there. What steps do you take first when drawing a head?
I dug up some examples online. Ideally you should use simple shapes to construct a head first. Then you can use a new layer to determine how you want to draw your face on there. And finally you can determine how you want to draw the hair. Where does it grow from the head? And how does it fall down?



If you have a basis sketched up beforehand, it's all a matter of taking small steps and adding details until you are satisfied. If you do everything at once it becomes difficult to get what you aim for.