Username isn't on Sharing and Permissions list for files

I was attempting to change the volume indicator sound (volume.aiff) in the Resources folder, but I didn't have permission because it's read only. So I went to 'Get Info' and scrolled to 'Sharing and Permission' but my username wasn't listed. I unlocked the file via the padlock, hit the + to add myself and my Mac tells me I don't have permission to do that either.

Upon further exploration I don't even have full permission access to my hard drive and I can't add myself there either.

Anyone know how to fix this? I did reset NVRAM and tried creating a new user account as well.