How can I change theme? I tried drush disable theme-name and afterwards drush enable theme-name, but it didn't work. 

How do you change theme with Drush?
For Drush 9.5.2 and Drupal 8.6.5 I use the following:

drush theme:uninstall THEME_MACHINE_NAME
drush theme:enable THEME_MACHINE_NAME
drush config-set system.theme default THEME_MACHINE_NAME