Simple Damage Script

I am brand new to Unity and a little overwhelmed.

How would one go about making a simple script that would be triggered by a mouse button or number key that plays an animation and subtracts health from an enemy without too many frills?

Ideally it would be a script where I could make different variations of the same basic script and assign to keys/buttons then drag all of the different versions of the script onto the player.

Any suggestions would be a wonderful help.

Also, any suggestions on resources to learn scripting?

Thanks in advance for reading this drivel.