setting up Yamaha MG12XU for Logic X

I am a noob. I had been using Apogee One for my single track recording with a simple pre amp inline. I play several different instruments and was getting tired of readjusting my preamp every single time for different instruments. I decided to get a Yamaha MG12XU mixer and have everything preset that way so I can just plug in and go.

That being said I have been unable to get the mixer to work as an interface. I have to be missing something. Logic finds my mixer for both input and output in preferences/audio. I would like to be able to monitor my sound after it has gone through Logic with the mixes but I am only able to hear the input going into logic. Anyone know the answer?

Thanks