Make a standard drupal 8 installation and enable all addons/modules/themes on the new site you require.
Make sure you have the following modules enabled:
I use drush in a multisite configuration:
drush -l https://uri migrate-upgrade --legacy-db-url=mysql://password@localhost/dbname --legacy-root=https://drupal7uri --configure-only drush -l https://uri migrate-import --all