The status.xml file is the file that shows the status of the game server that XLRStats is displaying the stats for. I use unique names for each status.xml file. For example, status_1.xml, status_2.xml, etc.
The status.xml file needs to be in a location that your XLRStats webfront can access. Personally, I set the location of status.xml to an FTP URL and created an FTP account on my webserver, where XLRStats is installed, so the status.xml is written into a folder inside of the webfront.
Here's what is in the xlrstats statsconfig1.php file for my 1st server (I have 4):
$b3_status_url = "http://grosskopf-servers.com/xlrstats/status/status_rtd.xml";
That tells the XLRStats webfront that the status_rtd.xml file can be found in the "xlrstats/status" folder.
Here's what is in the plugin_status.xml file in B3's conf folder:
<set name="output_file">ftp://ftpuser:ftppassword@grosskopf-servers.com/xlrstats/status/status_rtd.xml</set>
That writes the status_rtd.xml file to my webserver.
You will need to get the status plugin in B3 working before you set up XLRstats so that the config can find it when you get to that step.
I hope this helps.