In attempting to open App Store on my iMac all I get is a colored ball spinning endlessly?

Safe Boot, (holding Shift key down at startup), does the problem occur in Safe Mode?

Safe mode attempts to repair Disks & clears lots of caches & loads safe Drivers, & prevents loading of 3rd party extensions, so if Safe Mode works try again in regular boot.

If still a problem...

To find out if it's system wide or user specific, try this...

Open System Preferences>Users & Groups, unlock the lock, click on the little plus icon, make a new admin account, log out & into the new account.

Does it work in the new account?

I am having same problem.

i get the spinning thing to get in the app store, and trying to type a address in web browser on safari. I also cannot log in to my apple ID.

I have same problem for all three in safe mode, but they all work fine in the new admin account i made

By chance does your computer have any third party antivirus, cleaning or any other third party "maintenance" apps installed?

Any luck yet?

It still doesn’t work for me. I’ve got 5 updates I cannot reach in the App Store and my Catalina is the most current version. This has gone on for over a year.

Which exact updates?

Which exact updates are you wanting?