Can Drush make include username, password and settings in one file?
The responsibilities of Drush make involve downloading the files that make up your site.  Site initialization can be done in an installation profile, which is selected at installation time, or perhaps in a script that you run to set up your site.

For Drupal 8, configuration can be imported via the drush config-import command.  In Drupal 7, there are many options for managing configuration.  A lot of people (perhaps the majority) use features, but I prefer ctools bonus export.  Here is an example script I use to set up a test site for behat tests.

If you are just starting out, you might want to consider using Composer instead of Drush Make.