If you’re mic is mono, (not stereo), then you’ll only get the left channel.
If you want to add stereo effects to a mono recording, duplicate the mono track, (Press"Ctrl"+“D”),
then join them to make a stereo-pair, (which is actually called “dual mono” because the L&R tracks are identical).
Then apply stereo effects to the dual-mono track to stereoize it, e.g. pseudo-stereo , chorus, spin.