add drums track to prerecorded song

Anything that doesn't fit into other topics goes here!
I'm a beginner with LMMS and have managed to put my wav file into the song editor, but no sound comes. The difficulty, though, will be adding the drum track, since I don't play drums and don't know LMMS. The song is my own and has been edited with Audacity, my vocals and guitar. Can anyone tell me where I might find out how to do this? LMMS seems more for making whole songs, not adding instrument tracks to songs, and I have to use open source since I don't have the cash for things like Ableton.
Working with sample tracks is currently a bit problematic as they are an unfinished feature in LMMS, and won't be very usable until version 1.2 (next september) at the earliest.

For now I'd recommend using something like Ardour or Qtractor if you need to work with long sample tracks.
what diiz said, but one thing
but no sound comes
you need to first add the block in the sampletrack, and then drag a wave-file into that block.
When you do it correct, a wave-profile is drawn in the track.
In general, when it comes to writing percussion for any piece, you first and formost need to know the BPM and the time-signature.
That is a 'listen & clap' count' task :)
Then you can build the percussion in the Beat-and-Base-Editor component in LMMS.
If you like to learn more about getting started with LMMS, i have made videos for that:
https://www.youtube.com/watch?v=hcUCFfQ3wn8
and perhaps also
https://www.youtube.com/watch?v=jMPH5prCMv4
and there are several more