I have the same unibody MacBook and I don't have any issues with the App Store Updates. It is probably safer to install 2018-002 SU manually(read the first page of this thread).
Never updated my system: this is the state from the very first installation of High Sierra OS.
Also:
- my MacBook on each reboot plays the "boong" sound two times... is that normal?
- my network location list was wiped out installing High Sierra with the reported tutorial... is that normal?