New to sound

I apologize if this topic has already been covered... I'm new to Arduino Sound.

I purchased the pictured hardware and am having trouble finding where to begin. I'm interested in having one 5 second sound clip played 20 seconds after the Arduino is activated. I'm looking for help on how to:

  1. Connect the speakers to the MP3 player ( This MP3 player has a headphone jack while others have connections for external speakers)

  2. how to program the Arduino to play the clip 20 seconds after being powered on.

Thank you

Additional pictures for project

I'm interested in having one 5 second sound clip played 20 seconds after the Arduino is activated.

Does it have to do anything before this sound?
What does it have to do after this sound?