[GS] Making a Unique Unit and its modifiers

I've been following tutorials on how to make my own civilization, but I have no idea if I'm missing a list of modifiers or something. I don't get how I'm supposed to actually make a unit without knowing the stuff or code to make it up. I'm no genius programmer, so its way out of my field (not like I have one anyway).
So is there an actual list or something I can look at or do I need to keep guessing or try and find the correct solution online?
I really don't wanna have to write it all myself, I've been using templates since I couldn't find an actual guide that I could understand that took it from scratch.

What I'm trying to make specifically is basically a melee unit that does damage against specific types of unit. These units being everything below and equal to the Swordsman melee unit, the Pikeman Anti-calvary unit and the crossbowman ranged unit.