You must have an account setup on one of the emulab aggregates.
If you do not already have an account, guest accounts have been setup for this tutorial. Use the login information on the handouts.
The guest will have an account on emulab.net that gets you a protogeni account automatically.
You may also request an account by going to www.emulab.net and clicking on the "Request Account" button. Note that account creation in this case may require approval and may take a while.