Unable to open a new project

I’m a new user, who is very unfamiliar to the concept. I’ve followed every step that is shown the website www.ionicframework.com . I’ve install “cordova” and “ionic” successfully, but I cannot open a new project.
I get the following error.

yuhmeteriz@yuhmeteriz:~$ ionic start hello
/usr/bin/env: node: No such file or directory

(The OS that I use is ubuntu 14.04 LTS)
What should I do in order to overcome this issue?
Thank you for your attention.