Should I upgrade my iMac OS?

Q - " looking for software updates and keeps spinning "

A - An update would be, say Catalina 10.5.6 to Catalina 10.15.7

A - An upGRADE would be moving from macOS 10.15.7 Catalina to macOS 12.6.2 Monterey

To achieve an upGrade follow the below suggestion

The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install.  For Best results use Safari to commence the download as Others may not work.

Safari will open a redirect and open the Apple Store where the download can commence.

Computer Qualifying for macOS 13 Ventura 

Computer Qualify for the Monterey upgrade

macOS Big Sur 11 hardware requirements

macOS Catalina 10.15 hardware requirements

Make Time Machine Backup  is very useful 

Q - I cannot see the potential upgrades because the checking for updates ..... ball keeps spinning

Reply Helpful"

A - The user appears to have overlooked the Very Very important piece of the instructions.

A - Special Ink ➡️ How to get old versions of macOS ⬅️

Because the User did not or could not UpGraded when it may have been offered.

Apple has Removed the UpGrade for the Apple Store without the Special Link that is provided above