You were able to record the Mic signal. Great! So I assume you installed/configured the air 192 according to the user manual.
I didn't have that much time with my previous post. Let get in a bit more details now.
Signal paths can go like that:
Audio input device (ex: Mic) > air 192 hardware input > USB to computer > Logic Audio Channel Strip Input (Input Slot).
Logic Output > USB to air 192 > air 192 hardware output > Speakers.
The air 192 has a direct monitoring function. It means you hear what coming from its inputs not from Logic:
Audio input device (ex: Mic) > air 192 hardware input > air 192 hardware output > Speakers.
Turn off direct monitoring on the air 192 if you want to hear what coming from Logic.
To summarize, you create an Audio Track in Logic. This creates a corresponding Audio Channel Strip in the Mixer. You can also see it in the Track Inspector to the left. You click on the input slot on the Channel Strip and select an input corresponding to the desired hardware input on the air 192.
For the synthesizer, you may have to create a stereo track.
Hope this helps. If you need more help, do not hesitate.
WD