In Adobe Premiere Rush you can add music and/or sound effects to your video.
You can add music or sound effect using the Media Browser and adding the files as new Media. You can use music/sound effects you have downloaded, or use one of the free soundtracks available through Adobe Premiere Rush. Free soundtracks can be found under Rush Soundtracks in the Media Browser.
To add music/sound effects:
You may want to adjust audio in your video including voice overs, music and sound effects. Audio options let you do things like make audio louder or softer, reduce background noise and enhance speech. You can edit all audio using the Audio panel.