How do I move added audio around to time it with the video?

Hi all! musician here, I am trying to add a sound track (additional audio) which I have done but it is not in time with the video. The music actually started recording before the audio, so where the video starts, the audio is already part way into the song. How do I move (cut the beginning of the audio) and drag the middle of the audio to the start of the video? Thank you all so much for the help!  To try to further clarify, the video camera started after the audio recorder, the video starts part way into the song after the band started playing I need to lose the 1st part of the audio, and move the middle of the audio to the start of the video..