You should be doing this from the home folder
mkdir ~/bin < makes a folder bin
PATH=~/bin:$PATH sets the path
Just copy and paste that in terminal from your home directory. Nothing needs to be changed.
mkdir system is creating a folder called system, you can name it whatever you like
cd system changes directory to the system folder or whatever you named it.
Oh ok thanks for the help and all the tutorials
Sent from my Nexus S using XDA App