Upgrade
Can I upgrade from Yosemite to High Sierra on early 2011 Macbook Pro?
Question marked as
The 2011 MacBook Pro can upgrade to High Sierra.,
please use Safari to access the following link,
How to upgrade to macOS High Sierra - Apple Support
Before upgrading make a full back up of your Mac.
Check that third party apps you use have updates available for the new OS.
Check that your printers/ scanners etc have updated drivers and software available for the new OS.
Connect your mac to your router via cable rather than rely on WiFi.
Do not use your mac while it is downloading
and do not use any other devices that share the same internet connection.