3. Giving permissions for events
Then I went in and played with the configurations, of both Drupal and CiviCRM. Non-intuitive ones included that, in order to allow people to see and register to events, one has to give permissions from within Drupal (Modules → ‘Permissions’ link on the right of CiviCRM) to anonymous users, and unusual-sounding permissions at that: CiviCRM: profile listings and forms and CiviCRM: profile view (for the registration form in an event), plus the more intuitive-sounding CiviEvent: view event info, CiviEvent: register for events and CiviEvent: access CiviEvent.
4. Breaking the Drupal 7 admin
Then I went and downloaded and installed some new themes, because the default one is fugly (for me). Again, installation was non-intuitive (one has to paste the URL to the tar.gz file that can be found by clicking on the theme version number at the bottom of theme pages. Even explaining it sounds weird.), but even less intuitive was the possibility of breaking the Drupal administration by changing its theme 
In effect, I chose a different theme for it, and the pages kept loading, but the overlay which appears for any section of the administration failed to appear any longer. Looking into devtools, I saw that the error had something to do with jqery versions. Now, as I later discovered, through another dollop of searching through forums, is that the administration wasn’t broken, and that it also had a version without overlays that still worked.