Hello,
Also... I know absolutely nothing about the Nix/Git package manager that was recently added. Could someone help me get started?
you can find the documentation here:
http://genode.org/documentation/developer-resources/package_management
Further background information is provided in the release documentation of version 17.05:
http://genode.org/documentation/release-notes/17.05#Package_management
As mentioned in the release documentation, the package-management tools are still considered as experimental. The few official archives are merely provided as an illustration of the steps described in the documentation.
Cheers Norman