I have no clue where to start on how to make a kill counter everytime i kill an enemy, im new to unity please be kind XD
It OK to be new 
Answers isn’t really going to help you too much though unless you have a specific problem not a whole general area you need to understand.
As I recommended on your other post - go work through some tutorials. They will really help you to understand what is possible.
The basic element of the script would be to add a death() function to the enemy files that activates when the health<=0.
function death()
{
player.killcount++;
destroy();
}
make the killcount variable a static integer so that the enemies can access the value. To display the counter add the variable to the OnGUI() function.
I apologize if my notation is improper.