Hi and thanks for using Tribler!
Tribler automatically collects torrents from the network so if you run Tribler for longer periods, it will discover more content.
All information is stored in so-called communities. If you don't get results when searching, there might be a firewall issue. To verify this, you can open the debug panel (press Ctrl+d or Cmd+d on Mac), go to the tab 'Dispersy' and then 'Communities'. You should see the
SearchCommunity there, together with a number of candidates. Could you check whether the number of candidates in
SearchCommunity is higher than zero (i.e. you are connected to others)?