I need to update my computer to initialize microsoft teams

Click on Apple menu at the top left of the menu bar.

Click on About This Mac.

Click on Overview at the top of the window.

Read the line that starts with "MacBook Air" -- above the line that starts with "Processor" and look for the year there.

If it is a 2013. it can be updated to Big Sur. Click on the following: How to upgrade to macOS Big Sur - Apple Support

If not a 2013, reply back here with the model year.

A1466 applies to model years 2012 through 2017. The model year is shown in: What model year is your MacBook Air (from Apple menu > About This Mac)?

If it is a 2013. it can be updated to Big Sur. See: How to upgrade to macOS Big Sur - Apple Support

A 2014 can also upgrade to the current version of Big Sur. Click on the following for instructions: How to upgrade to macOS Big Sur - Apple Support

What model year is your MacBook Air (from Apple menu > About This Mac)?