Okay, right now I just followed this video tutorial:
How to Root Galaxy S4 using CWM Method! - YouTube
and everything was pefect until I finished everything and launched SuperSU,where I got the pop-up message:
"There is no SU binary installed, and superSU cannot install it. This is a problem"
I tried backing up on CMW recovery because I read somewhere that I should do that but still no luck...