how do i get a attack animation to work?
Take a look at here:
http://unity3d.com/support/documentation/Manual/Character-Animation.html
Basically just import your model file and do the setting stuff in unity.
Create a script for your animation and put it into your model.
Nevermind that “attack”, how to get an animation to work ? You need the Animation component, with at least one animation clip. If it’s a skinned character, the exporter must have created a skinned mesh renderer. To play it, either use playOnWake toggle in the inspector, or call it from script with animation.Play().