You still have to create an admin user, as far as i know it doesn’t get created by default.

Taken from https://docs.djangoproject.com/en/1.8/intro/tutorial02/ :

Creating an admin user

First we’ll need to create a user who can login to the admin site. Run the following command:

$ python manage.py createsuperuser

Enter your desired username and press enter.

Username: admin

You will then be prompted for your desired email address:

Email address: admin@example.com

The final step is to enter your password. You will be asked to enter your password twice, the second time as a confirmation of the first.

Password: **********
Password (again): *********
Superuser created successfully.

Hope this helps.