Next to a CalDAV server, you need access to a mysql or postgresql
database to use agendav.

Read http://docs.agendav.org/en/2.2.0/admin/installation/ for
installation instructions of the database.  This includes loading the
SQL statements using agendavcli utility.

Next you have to edit all config files in your installation's
  /path/to/hostroot/agendav/config.

Before you can use agendav, you need to upgrade the database (you also
need this on a new install) using:

  $ /path/to/hostroot/agendav/agendavcli dbupdate