You can search for a torrent with your phones web browser like you would normally on your computer, download it to the phone then load it in to your torrent client that you installed. It will start to download in the background while you do more important things. Your going to need a bigger SD card as with all downloading memory is key so make sure you check file sizes before you start. Your not going to fit 15gb on your HTC Wildfire internal memory!
All you need to get going is one of these great clients available in the Play Store. uTorrent or Bittorrent. Install either of these then search your normal sources for legal torrent files and start downloading.
All files will be stored in a preset directory in your phone and once you connect your phone to your PC you can search for your downloaded files and you can copy them to your desktop, simple as that.
The clients are very straight forward to use and installing them is a breeze, just keep and eye on your memory, battery and if your trying this on mobile data keep a close eye on your data usage as this will eat through any data cap quickly if you start downloading a lot of information.