This might seem a little irrelevant to ask, here did you get those sprites of that girl?
Anyway, considering that you started on in CGI, it's not as difficult as you think to transition to 2-D animation. Sure, you have to do each pose by hand as opposed to relying on sophisticated tweens, but the general principle of animation is the same for any type of media you deal with. All it takes is getting used to it.
I can't really help you with 2-D animation as much as you would like, so what I would suggest is studying how the animators from Disney and Warner Brothers animate their characters by watching the shorts. Just play each one frame by frame to study how the illusion of moment is achieved, break it down, and try to emulate it for yourself. Also, it wouldn't hurt to take a peek in any animation guidebook you could find (most mainstream animators would recommend the Animator's Survival Kit). Even though the concept and principles of animation are simple enough, it takes practice and proper guidance in order to reach a point where doing it by yourself is easy.
Anyway, considering that you started on in CGI, it's not as difficult as you think to transition to 2-D animation. Sure, you have to do each pose by hand as opposed to relying on sophisticated tweens, but the general principle of animation is the same for any type of media you deal with. All it takes is getting used to it.
I can't really help you with 2-D animation as much as you would like, so what I would suggest is studying how the animators from Disney and Warner Brothers animate their characters by watching the shorts. Just play each one frame by frame to study how the illusion of moment is achieved, break it down, and try to emulate it for yourself. Also, it wouldn't hurt to take a peek in any animation guidebook you could find (most mainstream animators would recommend the Animator's Survival Kit). Even though the concept and principles of animation are simple enough, it takes practice and proper guidance in order to reach a point where doing it by yourself is easy.