I can't set up an audio input for recording even though my mic is hooked up

I plugged in my samson go mic into my computer, and it told me in order to record i have to have an input set up. Then i would be able to arm the track and record. But when i go to input, i can't click on one of the options. How do i set up an audio input for a track?

Please note my other post about going through the on-line tutorials.  They have an example specific to your Sampson mike.  These tutorials are very good and well worth the time going through them.