CQ-20B Signal routing

I am a new owner of the CQ20b and will be using it first time tomorrow for a band rehearsal. I want to record all channels that have audio input as a multitrack to an SD card. The only channels I want to hear from the main speakers are vocals, as we are in a small room with instruments and amps. How would I accomplish this?

Thanks JR

Regarding the recording, we can certainly assume that you have also read the two relevant pages 134/135 in the User Guide.
What questions arose afterward?
The best thing to do is try it out today at the latest.

Open only these vocal channels in your Main LR Mix.

Thanks I think I get it now.