django - what should you do if you don't need a database engine?

You are required to use a database engine if you want to use some features of django, like sessions, for example. If you do not need those, just remove them from middleware classes.

If you want to use sessions or store some data using django apps, but do not want to do all the complicated database configurations, you can use sqlite3 as your database engine. It does not require any setup, all you need is to specify a path, where database file will be created and stored. Thats it:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3', # Add 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
        'NAME': '/var/www/mysite/sqlite.db',                      # Or path to database file if using sqlite3.
        'USER': '',                      # Not used with sqlite3.
        'PASSWORD': '',                  # Not used with sqlite3.
        'HOST': '',                      # Set to empty string for localhost. Not used with sqlite3.
        'PORT': '',                      # Set to empty string for default. Not used with sqlite3.
    }
}

Can you list a SQLite database there?

Although I would consider, if I were you, if using a heavyweight framework like Django is appropriate for the task you intend it for (because you don't even need a database).