Unity's default Toon Shader with transparency.

I'm new to shader coding.

So I've found code online where people can add an alpha to the outline of a toon shader.

But how should I go about getting a 'Toon outline lighted' shader that has adjustable alpha for the outline AND main color? Thus allowing me to make the whole toon shaded object 0-100% opaque?

Also what's the best way to get started with messing around with shaders? One of my other future goals is making my own cel shaded smoke effect.

 

How do I add an alpha channel so I can bring the opacity of toon shaded objects to zero in C# script?