can't create virtual env in ubuntu 14.04

Question

Initially I followed this user's Q&A - How to set up and use a virtual python environment in Ubuntu?

but this didn't work at all. When I do

mkvirtualenv -p python3 test

I get this

ERROR: virtualenvwrapper could not find virtualenv in your path

So I want to know

1. How to remove all the changes I did following this post
2. How to set up my environment so that I can use this tutorial:

How to install the Django web framework on Ubuntu 14.04