Isolating Tracks How To?

Im pretty new to this Mac thing and was trying to play around with Garageband earlier.
I was wondering if there was a way to isolate parts of a track and pull out that bit of music as its own file using Garageband?
Thank for any help!

Copy and Paste.
Copy the section you want to copy by highlighting it and clicking command + C.



Paste it by starting a new project and in the track that you want it click command + V.

I just realized that you are probably trying to isolate bits of other musicians tracks.
I believe you will need help from some of the DJ folk on here, and also keep in mind respecting copyright laws.