Mark, why not leave the meter alone, when shooting outside, maybe using aperture mode, the camera will choose the shutter speed, check the histogram and work from there. They look far more than 2/3rds of a stop underexposed to me. My mate has a D600 and the metering is very near, so I guess the D750 definitely will be.
As regards the club portraits, I too felt awkward at first, but it's a nice learning curve, at our club our photographer sets up the lights meters and gives out the exposure, we set our cameras, obviously in manual mode, then we shoot, check the image and adjust, our photographer is very helpful especially to all new photographers, he is going to run some lighting workshops too soon. Maybe you might enjoy doing a course, or get a few together from your club and help each other, you will love it