Elderly newbie to Sansa Clip+ how to start instructions -- where to put songs?

I am a senior and was given a Sansa Clip+ 8Gb to use in Physical Therapy.
It has a microSD card.
How to start – playlists, etc.
Where do I store the songs? Internal or the MicroSD?
Will this MP3 see the songs on the MicroSD?
Please simple instructions.
Thanks