Torrenting inherently involves risks that go beyond simple file sharing:
First, you need to find a reputable torrent site. Some popular ones include The Pirate Bay, 1337x, and YTS. Be cautious and choose sites that are well-known and have good reputations to minimize risks.
Once on the site, search for "The Avengers" or more specifically, "The Avengers [Year]" if you're looking for a particular version, like "The Avengers 2012."