You are getting a bit ahead of yourself here.
Before entering logic, you somehow need to get the microphone signal into your computer, via some Microphone preamp and then a converter.
All those logic settings won't really do anything. But you need to select the correct input, as where you are connecting your mic.
The buffer size won't affect your recordings at all, altough it will affect your monitoring, if you are monitoring trough logic.
24. bit is reccomended, software monitoring and independent monitoring is just depending on what you want/need.
Process buffer, rewire and scrub have nothing to do with your mic or connecting it to logic.
to record a vocal mic:
Plug the mic into any preamp/interface
Connect the interface to your computer, set up correct drivers and so on, Or connect the line out of your preamp into the Line in on your computer (the first methood is prefered tough)
Select the proper audio device in logic.
Make a Mono, Audio channel, and assign it's input to whatever input you connected your mic to. Record enable the channel. Wach out that you are don't have your speakers to loud/mic to loud/mic to close to speaker or you could get nasty feedback)
Check the gain staging of your mic (turn up/down the Preamp so that the mic isn't clipping (going over 0.0, turning red) and isn't to low (-30db is to low, try to keep it's running around maybe -15 to -5db at the most)
press record