Audio player?

Is it possible to make an audio player with an sd card and an Arduino nano? If so could you give some guidance

Yes, look at these MP3 player modules.
http://www.mdfly.com/search.php?search_query=mp3
Send a simple serial command at 4800 bps to start a song playing, also supports stop, pause, etc commands.

Is an MP3 module needed

dustyloshe: Is an MP3 module needed

Absolutely, unless you are happy with a buzzer kind of sort of playing music one note at a time.