How do i start a music at 30sec using audacity?

I put 2 songs together w/ audacity, but i wanna know how can i put one of them starting at 30sec ?|||There is a time-line. Just drag one of the songs forward (after you select it).|||Ok, on audacity, you need to record the first song that you are using, then when its done recording press stop, for the second song click on the timeline of the song at 30 seconds, and start recording that second song,it automatically starts on a different track, so this will work (I experimented with audacity to figure out your question and it worked). By the way, you must click stop recording for the first song dont pause or it wont work, and click record to start recording at 30 seconds. It will work! Hope this helped.