i need to upgrade my MAC to download payroll apps. how do i do this

Your mid-2014 iMac can be upgraded to the latest version of macOS Big Sur, 11.7.5, but no further.

However, to upgrade beyond 10.14 Mojave will require that all of your apps and software meet the standard of 64-bit coding. This will include any Microsoft Office apps that you use. There are alternative to MS Office apps for Mac, including Apple's own Pages, Numbers and Keynote apps, which you can find in the App Store.

❗️ Do NOT upgrade…

until you have made a Time Machine or other backup of your startup drive.

Learn How to Back up your Mac with Time Machine

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 of your screen and choose About This Mac.

Check the Compatibility of your Mac with newer versions of macOS:

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

➡️ macOS 10.14 Mojave is compatible with the Macs listed here

➡️ macOS 10.15 Catalina is compatible with the Macs listed here

➡️ macOS 11 Big Sur is compatible with the Macs listed here

❗️ – IMPORTANT – None of your 32-bit apps will work in macOS Catalina or newer.

32-bit app compatibility with macOS High Sierra 10.13.4 and later - Apple Support

Use the free utility Go64 to check the compatibility of your apps:

https://www.stclairsoft.com/Go64/

✅ - IF your Mac is compatible, then download the macOS upgrade installer app:

Click > High Sierra,  Mojave,  Catalina,  Big Sur.

Once downloaded, double-click the “Install macOS…” app in the Applications folder to begin the upgrade.

Please see > How to download macOS.

you use app store to update to newest macos

Update macOS on Mac - Apple Support

though depending on the year of the mac it may not support latest version

IF you want very specific answer, please tell us the iMac sub-model and current macOS version. Both are critical to our evaluating your upgrade path, if any. Many older iMac cannot run a higher OS than 10.11.

That may also cause updated minimum system requiremetnfor your payrol app to be an issue.

The information we need to tailor an answer to your exact requirements are quickly available from "About this Mac..." under your Apple menu: In OS 10.11:

For security reasons please DO NOT post the serial number here, That will get the image redacted and we'll be back to Square One: having to guess.

What are the system requirements for the payroll app?

As you are so far behind, it may be helpful to first upgrade macOS 10.13 "High Sierra."

Thank you. Then that should not be an issue using the How to download macOS link at the end of D. I. Johnson's post