Not too sure about your question....But start here for live vocals:
Plug a dynamic mic into the XLR on ch 1...Crank the input twisty to minimum. Set all Eq twistys to 12 oclock including the pan....Then rap into the mic and crank the input twisty unill you get a blinking led on the input level
Reduce all sliders to minimum...Then increase the masters to 0/unity....Then increase chan 1 slider till you like the sound pressure....From there control level with the masters....Play with the Eq twistys and adjust the input level as you do cause whenever you boost the strip Eq you will need to to reduce the input gain...If instead, you cut the Eq, you might need to increase the input gain.
A shortcut you might want to try is to start with masters at unity, then inputs at 0, increase mic slider to -6, then increase mic input to get sound level you like, then Eq and readjust input...finally use masters to attenuate as required.
Never run with channel sliders higher than masters.