Changing volume of vocal in recording

I am using Audacity 2.1.1 in Windows 10. I have a 17 piece band and have recorded songs using Audacity to edit wave files and put them on CDs.
I wondered if it was possible to elevate the volume of a vocal track on stereo recordings. ( I see you can eliminate, or reduce vocals.) I installed
Audacity using the .exe installer.

I see you can eliminate, or reduce vocals.

Yes. People see that and naturally assume if you can reduce vocals…

You can’t. It a trick of audio that under some conditions, the left and right of a stereo show can be made to cancel anything in the middle—usually the lead vocal, but sometimes drums and bass, too. Less known is the show that remains isn’t stereo. It’s mono and that pretty much kills any chance you have of using this as a production tool. Any effects you derive are not applicable to the original stereo show.

This is why people doing live recordings generally have a recordist there to balance the performance, or multi-track record and balance it later at home.

That isn’t to say you can’t try. Audacity 2.1.1 also has Effect > Vocal Reduction and Isolation. This is a full-on production effect that needs to be balanced and adjusted for the performance. It’s not set and forget. It tries to recognize the voice character and manage it independent of the rest of the instruments.