Post-installation instructions:

To make WebCalendar workable, please read
%%DOCSDIR%%/WebCalendar-SysAdmin.html
for information about creating the database, installing
the database tables and other post-installation tasks,
such as setting up email reminders.

Then copy
%%PREFIX%%/%%WEBWCDIR%%/includes/settings.php.orig to
%%PREFIX%%/%%WEBWCDIR%%/includes/settings.php and edit it
for your installation.