Upgrade the macOS 10.12.x
How do I Upgrade the Mac operating system? it may be a big step and may cause things to stop working.
Verify your Time Machine back up before you begin, and consider added ways to protect your data.
AND… Research your situation and related upgrade experiences. You decide, if ‘upgrade features’ may be worth any risk.
Apple makes it easy to get full operating systems and updates… Apple menu > App Store
Type Your Apple ID and Password to request the operating system to download and begin the installation. It’s a large download, and may take upwards of 20 to 40 minutes to download it. Once downloaded, and… click Continue, click Agree, click Install, and type your Mac password click OK … You may need another 20 or 40 minutes to install it … And your computer may restart a couple times before completes.
Afterwards log into your account, and check your printers and scanners. Make sure you’re on the network…