Flexget, how does it work? I got a new seedbox and it offers the program

Back on my other seedbox, I would use rutorrent's RSS Downloader for the trackers that did not have a autodl-irssi service. It was okay, but clunky, and would not automatically download, i'd just get a big list of the last 25 newest torrents and I'd have to select them myself.

Now I installed Flexget the way whatbox says to, but what then, I haven't noticed anything new in rutorrent, so this is something that has to be used in the ssh connection. I have no fear of using the terminal, but I got no idea how to use Flexget, whatbox include the installation steps only.

Thanks.