iTerm2 & Terminal show my Mac serial code
You want to modify something called the prompt or PS1.  You can see the current value by typing echo $PS1 To get rid of the first part you don't like and leave only the user name type export PS1="\u"  If you want to persist the next time you open the terminal, you would write that line in ~/.bashrc   A detailed walk through is here http://osxdaily.com/2006/12/11/how-to-customize-your-terminal-prompt/