Processing vocals in AudacityEdit
Import your audio file.
Amplify the whole track as much as possible if helpful.
Get noise profile, then use Noise Reduction.
If your peaks are uneven in an undesired way, use limiter some, and then amplify the whole track. You can limit just a little bit at first, and limit more and amplify more if helpful.
Add any more desired effects.
Export your audio file.