This wasn't too bad actually, if this is really your first animation, then you're off to a good start! The animations looked pretty decent and the fight was OK too ( I guess), but you should make the characters react to the attacks a bit more, especially when the guy with the sword was on the ground or in the air getting sliced up by the white stickman, he was just standing there not reacting to the attacks at all as if he was just a part of the background. Also, the sound effects a bit too repetitve.
Also, I think you should try to add more details to the background. Also, I think you should make the attacks look a bit more realistic. Also... ehm forget it. Just know, that this is a good start :^)