First, make sure the plugin is enabled. Seems simple, but people forget to enable plugins all the time
Then make sure you have selected a list to subscribe registrants to. Then save the plugin.
Text on top of the event list?? Are you referring to "Below is a list of all events that are currently open for registration. Click on the event name to proceed."?? Any text, including that, is changeable in the language file:
/language/en-GB/en-GB.com_dtregister.ini
Oh, please try to keep a forum thread on topic