I've got basic goals for a small game and need some direction.

I have the basics of C# down, the bare basics - I know how to get the player’s input and turn it into a modification of the object’s transform and rotation to make a basic controller.
But can someone start me off with some basic syntax or methods or maybe tutorials to look into for the end goal of my character controller?

If the player press the fire key, they perform a melee attack.
If the player object receives an attack / is in range during a certain frame of the attack’s animation, remove / kill the player object, unless the player blocked or parried. (which i would have other inputs and animations for)
If the player parried, trigger a new attack that will kill the enemy, unless they dodge. (hoping for a dodge roll in the end)
If the player blocked, play appropriate animations for both players involved, and cancel any attack until the animations are complete.
How hard would this be?

Maybe you missed this section of Unity website ?
https://unity3d.com/learn

You can find in the tutorials everything you just noted and more.