Upgrade Mac OS from El Capitan to Sierra How can I find the build date of a serial number like W89072N87WY to check if an upgrade from El Capitan 10.11.6 is possible. 

What’s the process to check for Sierra?
Apple has machine friendly names for Sierra  here. 


https://support.apple.com/en-us/HT208202


Since you didn’t show that, use Everymac's Ultimate Mac Lookup

This is a MacBook "Core 2 Duo" 2.0 13" (Unibody), maximum macOS 10.11.x - so, no, it's been upgraded as far as it will go.