I want to put music to my video, which is 6 minutes long, but my music is 3 minutes and I can’t figure out how to put the music to all of the video…
Create an audio track [ctrl+u]
Drag the audio to the track.
Copy the audio on the track to the clipboard then paste a copy at the end.
I did that, it erased all of the video and audio from the timeline.
Well you made a mistake, try again 