Software to use for audio and video editing

Audition only edits audio - you can't do anything video with it. But it's way better at editing audio than Premiere is. So if it's simple audio, then you will have to use Premiere. It's also possible to export audio from Premiere into Audition to be worked on, and then replaced - it's called 'round trip' processing. To do this, you need to have version numbers aligned.