FUNDAMENTAL VIDEO TIPS
Whether using ambient light (e.g. Sun or a window) or lighting devices, the light source should shine upon the Subject's face.
Unless you have a specific reason to use one over the other, TRY BOTH, to see what would work best.
Don't neglect the scenery behind the Subject. Make it interesting! But, don't make is distracting to the Viewer.
Remember, Sound should take priority over the Image. Get as close to the Subject, as possible to get good Audio.
The head of your Subject should almost touch the top of the frame.