How can I move sphere along Bezier curve?

Your picture did not post: "Access to the specified resource () has been forbidden." iTween is a free package that has support for moving objects along a path. There are more sophisticated packages for purchase. (SuperSplines has been mentioned on this list). But if I understand your goal correctly, you might be better just using Unity's physics engine or implementing your own gravity.

The best way to achieve the movement is to use the physics engine, not try to move the ball along a specific curve. Research Rigidbody.