There is a setting on the "object properties" tabs for everything you have in a scene that allows you to turn on or off shadows for it specifically: or, you can do it for individual lights to totally eliminate shadows in a scene.  Just double click the item in the scene and the "properties" menu will pop up and uncheck "shadows on that tab.  In the case of lights, you can do the same by clicking on it's properties or you can manipulate the shadows intensity by the parameter dials.

I hope this answers your questions.

Larry-L