Are you sure that's your first flash?
That's actually suprisingly good for a first flash. Congratulations, you're a flash artist. Really my only grudge with this was the frame rate. Next time you try something like this, crank up the framerate (number of frames per second) to make the animation seem smoother and faster. This one seemed a little bit slow and groggy. Increasing the framerate (and with it, the number of frames in between a character moving or swinging a sword from point A to point B) creates a faster, more urgent pace vital for fighting animations.
Superb work, though, if this really was your first flash.