How do I determine whether to import a file in an mono as opposed to stereo. I figure if the file I am importing has a left and right I need to make it stereo. What about vocal, would I import that as stereo. Is it all or nothing. All mono or all stereo in a project?

A vocal track is typically mono as a sound source. As would be most guitar and bass sources. There are VOICES in the synthesizers nowadays that are recorded in stereo and would benefit from your recording them as audio in stereo. The main piano sound is typically sampled in stereo. Many of the String Orchestra sounds are sampled in stereo. As are some of the Drum Kits.

Any Voice that uses a stereo effect, of course, even if the sample is mono would benefit from being recorded as stereo audio. For example, take the Rhodes Electric Pianos that utilize a STEREO PHASER, FLANGER, DELAY or AUTO PAN… the B3 Organs that are run through the ROTARY SPEAKER effect type (you don’t really hear these unless you maintain the STEREO signal flow).

Your ears are the best detection tool about which sounds are stereo. If you are not adept at hearing it immediately (consider new speakers - highly recommended when mixing are “studio monitors") - you can verify the source by calling up a VOICE and looking at the name of the WAVEFORM.

Call up the VOICE
Press [EDIT]
Press numbered button 1 to view the ELEMENT 1 parameters
Press [F1] OSCILLATOR
Here you can see the name of the WAVE used to create this VOICE - if you see the letters “St” at the end of the Waveform Name you can conclude that this Voice is made from Stereo Samples..

Other Voices may also be stereo depending on how the programmer created the VOICE - learn to explore the VOICES so you can tell. VOICES can be made up of as few as one ELEMENT and as many as eight ELEMENTS. Each Element can be panned individually in the stereo field.

To maintain a Voice’s stereo-ness you must record it as audio using both the left and right outputs. So unless you recorded your vocals with a STEREO microphone, or are using a STEREO Effect, it is most likely a mono source.  By convention, vocals are typically mixed to the center of the stereo field - this is what is done most often, but it is not an ironclad rule. You can do whatever you like!