I need to connect/ turn on my audio to my audio interface.

Hi, so I so I just downloaded the Audition 1.5 software for my internship. I also just setup the scarlett solo audio interface on my computer. Now I need to connect the audio. The scarlett solo comes with tutorials and instructions for almost every other type of software, but Audition and sence this is an older version I have had trouble finding anything on it myself. I am still really new to all this, so I need some step by step instructions.