Simple 3 point lighting rules for a talking head. I took these from a video, published here as notes for myself only. Don't take lighting advice from me without double checking!
First light, right or left (maybe camera's left best?). 45 degree angle, a bit above the subject if you want Rembrandt's triangle. No sharp light, since it casts sharp shadows
Second light, same setup but opposite side. Less light.
Third light, directly opposite first light but higher up, out of shot.
Background should be darker on the more lit side of the face. Background overall in between the brightness of the left and right side of the face of the subject.
Background can have complement colours, each side.