Try using non-anime/comic references too when you draw, that way your fanarts and manga inspired work will be from an anatomical point of view and you'll develop a more personnal approach too. Give your instruction book a second try. Also, for the coloring part, if you're going to leave white spaces like you did, which JJorgie mentionned the scratchinest of it, try going for more delicate, parallel lines when using crayolas. You can also go with cross patterns, that will end up fill the unwanted white spots. I personnally don't mind the white spots if they're done in that matter. You can also make the coloring more filled where there's shadows and less where there isnt, also where theres a direct light impact. Well, I guess that's what I wanted to say Draw more! The more you draw, the better you'll be!