Thanks cam_0
this link detailing the rough requirements for each version of MacOS might be helpful:
https://www.macworld.com/article/673697/what-version-of-macos-can-my-mac-run.html.. then verify the capabilities of your Mac by going to “About this Mac” under the Apple icon, top left of your screen, and it’ll tell you stuff, take a screenshot ( Apple+ shift+3 held down together or Apple+ Shift+ 4 ( you should hear a “camera click” if successful, ) then take that info to everymac.com which will tell you the specs and useful
info about pretty much every Mac made… then download the appropriate version of MacOS for your Mac from this link; you should use Safari for downloading this, as it links right to the App Store… other browsers may work, but you’ll have to point ‘em to the App Store… here’s the list of Mac OS ‘s
——>>>> How to download and install macOS - Apple Support (CA)
( up to Mac OS 13 which is Ventura, the latest stable version of the MacOS)
John B… maybe you can upgrade the RAM ( memory ) on your Mac, who knows??