Hello - I am new to MK. II. Below is what I am not able to do and hope to get help.

I am not able to set the exposure while setting up the shot.

I can ONLY change it when I have the record button pressed.

If you are shooting in manual mode (which you should be) then as you are in the US you should have shutter speed at 1/60 then you can adjust aperture with the big wheel on the back & ISO by pressing the button on the top on the far right then using the small wheel on the top to adjust the value. You have probably had the camera in P mode.