you're too focused on animating only the limbs to where the entire thing feels static and disconnected. You have to move all parts of something to make even a basic walk cycle work!
I reccomend starting with stick figures, they're an excellent way to reduce the stress of the learning process while you're figuring out how to properly make bodies move. Then once you've got some of that down, move on to basic shapes and finally more complicated creatures like this drawing!
