TorrentsDB or Kickass torrents would be good places to start. Be aware, though, you might find that your ISP has blocked access to those sites, The way to get round the above is to download TOR anonymous browswer and use that to navigate to the site and download the torrent, Once downloaded, then open a torrent client. Transmission is installed by defualt. But I don’t particulaly rate it. A better one is qbittorrent. You can install that from the software centre.
A typical popular movie of, say, 2 GB size, will take about ten mins to download.
I should also say, using torrent clinet is a very good way to get hold of Linux ISOs. a heck of a lot faster than direct down;oading, as well as saving bandwidth (and therefore money) for the Linux providor.