My Macbook Pro is a Mid 2012 and I would like to upgrade to a higher OS than Sierra

Do NOT upgrade until you have made a Time Machine or other backup of your startup drive.

How to Upgrade  macOS:

The macOS version you can upgrade to depends on the year your Mac was released.

Click the  (Apple) menu at the top left of your screen and choose About This Mac.

macOS 10.13 High Sierra is compatible with the Macs listed here:

https://support.apple.com/kb/sp765?locale=en_US

macOS 10.14 Mojave is compatible with the Macs listed here: 

https://support.apple.com/kb/SP777?locale=en_US

macOS 10.15 Catalina is compatible with the Macs listed here: 

https://support.apple.com/en-us/HT210222

❗️ – IMPORTANT – Backup your data, now, before you attempt an upgrade.

Learn How to Back up your Mac with Time Machine:

https://support.apple.com/en-us/HT201250

❗️ – IMPORTANT – NONE of your 32-bit apps will work in Catalina.

https://support.apple.com/en-us/HT208436

Use this free utility to check the compatibility of your apps:

St. Claire Software – Go64: https://www.stclairsoft.com/Go64/

🖥 – Check compatibility of your Mac with newer versions of macOS.

https://support.apple.com/en-us/HT201475

✅ - Using Safari only, download the macOS upgrade installer app:

Click > High Sierra, Mojave, Catalina.

Once downloaded, double-click the installer app in the Applications folder to begin the upgrade.

Also, to add the following comments, if your Mac will not accept Big Sur, it will not accept a newer operating system as it will have topped out. Incidentally, at this time Big Sur is the latest release. Monterey is the next one, but it has not been released yet.