How to create test users on the localhost?
To add new user you can go to admin/people/create (localhost/YOUR-SITE/admin/people/create) and create the user, you don't need to enter a real email. And if you want to test the site with different users you can use the Masquerade module.


  The Masquerade module allows site administrators (or anyone with
  enough permissions) to switch users and surf the site as that user (no
  password required). That person can switch back to their own user
  account at any time.
  
  This is helpful for site developers when trying to determine what a
  client, logged in as themselves, might see when logged into the site.