Adafruit audio fx sound board with amp

Hello all, new here. I am interested in the above item but am very much a newbie to all of this. I have 2 questions:

Is it possible to put files on this using an Apple Mac computer? The instructions state a Windows computer but I only have a MacBook

Once all connected, is it possible to control the volume going to the speaker?

Thanks

Like I say, I am very much new to this so apologies if I have done anything wrong.

Thanks

David