I finally took the plunge and bought a new 2015 MacBook Pro Retina. I'm setting it up and was looking at the storage usage and it says there are already 1.31 GB of audio, 745 MB of photos, and 409.4 MB of movies. I haven't loaded anything onto the computer yet, so I'm wondering whether should I worry that my computer was used and returned? Are these just built in files for the OS, and is there a way to delete them to open more space? This is my first Mac, so I'm not familiar with how to find out what these files are other than Finder (there's nothing listed there under All My Files or Documents).