Drupal Console: Install a new site

drupal site:install \
  --learning \
  --uri="http://testing.site" \
  --langcode="en"  \
  --db-type="mysql"  \
  --db-host="localhost"  \
  --db-name="drupal8_site"  \
  --db-user="somesiteuser"  \
  --db-pass="really secure password"  \
  --db-prefix="prefix_" \
  --db-port="3306"  \
  --site-name="Drupal 8"  \
  --site-mail="admin@example.com"  \
  --account-name="anything but admin"  \
  --account-mail="admin@example.com"  \
  --account-pass="another really secure password" \
  minimal # the profile name

The --uri= option is needed when dealing with multi-site.

The drush version

drush site:install --db-url=mysql://username:password@dbhost/dbname --account-name="anything but admin" --account-mail=anybutadmin@example.com --site-mail=noreply@example.com --site-name="Site Name" --sites-subdir=multist minimal
--db-url=mysql://username:password@dbhost/dbname
The sql url needed to connect to the database
--account-name="anything but admin"
Admin is the default installed username, so use anything but this!
--account-mail=anybutadmin@example.com
Email address of the above admin account
--site-mail=noreply@example.com
Email address used by the site to
--site-name="Site Name"
The site's title/name.
--sites-subdir=multisitedir
The directory inside the sites direct to place the site files.
minimal (profile)
The profile to install for the site. This can be one of the core profiles, or an additional one.