So I'm new to unity and i am finding animation way to hard. I have downloaded this zombie pack(https://www.assetstore.unity3d.com/en/#!/content/30232) but i don't know how to configure it plzz tell. And also tell me how to play the animation and what video player is used in it thanx in advance

Unity is game making software, and not primarily animation software.

If you're interested in 3D animation then I would recommend C4D / Blender / 3DS Max / Maya.

What are you looking to achieve?

Yea if you're going for animation, use some of the tools the ones before me mentioned. Unity doesn't specialize in animation.