I registered in this site yesterday and i tried to download some files but they don't start....I put them into my bitcommet and start them but the downloading speed stays at 0kb/s. Please help me

make sure you download the files that have more seeds. show me which file you're downloading. i think you chose the ones that dont have seeders online.

There are a million possible reasons for this, it would be good if you where more specific.
Are you downloading from other places and do they work? Is the problem unique to this tracker or for all torrents in general?
Make sure your firewall is not blocking utorrent and that you are on an open network.