Hey Michael. Believe it or not - moving your light further back would make your shadows more harsh. Think of it this way: Take a flash light and set up a cup on a table. Move the flashlight closer and further away from the cup and see which produces softer shadows. The closer you get your light source, the more the light wraps around your subject. The further away you get, the harsher the shadows get because your light source to subject size ratio is smaller.
In our minds, the sun is a massive light source, it produces a lot of light, but it is so far away that it becomes a "small" light modifier and that is why shadows on peoples faces are terrible during midday sun. On the contrary, overcast skies and clouds act as a massive light modifier and soften the light, bringing the light source closer to us, and spreading out the light, producing much softer shadows.
Hopefully that makes sense. As far as a modifier - get a good shoot-thru umbrella and start shooting. That is the best place to start!