this is great for a first oekaki! i'm guessing you've been on BBCode websites before, too, because you seem to be getting used to that ^^
i'd say you should open an art shop. because you have a signature, you can advertise it there. any people who like the shop might also advertise for it, and you'll have a working shop!
EDIT: i think the tail is perfect, actually, but you might want to make the legs a little thicker.
when i make my drawings have skinny legs, my brother says 'if they were real, they would all die because their legs would snap off!' after that, i always make my legs look better. c"x