No Audio

Hi Guys,

I am extremely new to Cubase am in the process of producing my first piece. I have no playback sound. I have fiddled with all of the settings although wonder if the issue is my speaker setup. My speakers are Klipsch THX and plug in via a stereo jack. I am getting no sound from any of the inputs. I get sound playing back from other things such as you tube, Spotify ect. The speaker configuration is left, right and sub. Would it be the case that these speakers are not possible to be used? I also assume that I can listen to playback with my head phones. This is also not working.

Any help would be amazing as I would love to start making music.