M-audio profire 2626, iMac, Cubass Al6

I am using an M audio profire 2626 with an iMac and cue bass Al 6. I am having a huge troubles assigning inputs on the software. Nothing lines up or makes sense and I can only get one channel to work. I can’t not assign the 8 tracks to the channels on the interface and the input labels don’t match on my Vst connections. For example, there is no input one for track one. Is there a trick with the iMac that I am not using. Any help would be great.