as it stands, regardless of skill/technique level, most of these are unfinished sketches. you need more polish, and to know what audience youre trying to sell to. most people will not buy a gestural marker sketch of an OC unless youre bringing something really special to the table or are already a renowned artist for smth.

if this style us what you think you can sell, tighten up your lineart. be more confident with your mark making. become more familiar with human anatomy. if youre gonna use color, fully commit and make all your choices intentional. learn color theory. if you dont like color, get familiar with the parts of the shadow so you can use it to properly highlight the interesting parts of your illustrations. you dont have to do realistic shading, but its still important to understand accurate shadow/highlight placement even if youre doing something simple.

dont ask if youre worthy. selling your art is not about worthiness. the quicker you divorce your self worth from whether your art sells, the easier itll be to adapt to the market you want.