No you don't have to pay for the torrent that you download ^^
Here are two of the most commonly used torrent software:
(download any of these two first)
BitTorrentuTorrentYou just have to click on the DOWNLOAD button.After you have got any of those two, THEN you can go browse around for what you want.
There is a little search box there, just type in the keywords and you'll get it ^^
But just in case you dunno where to find those Torrent site, here are a few links:
The Pirate Bay (My Ultimate fav site)
IsoHuntFlixFluxAlright.. So I hope these helps ^^
There are other Torrent sites.. Just google for it and you'll find them.