changing volumes on sound clips

Hi, I’m just learning how to use audacity and have a question. I have two sound clips I’m playing, I want one of the clips volume to start loud, get soft or go down so the other clip can be heard, then get loud again when the second clip playing in the middle is done. For the record its applause (loud), then a voice (loud while applause is quiet), then applause loud again. Any help or advise would be awesome, thanks in advance!

See the “Envelope Tool” in the manual: