computer partitioned, CS6 orbiting

I recently had to have my iMac partitioned, part on Yosemite (old OS, obviously), part on Big Sur (as new as I could go on my late-2014 iMac). I need to keep the Yosemite part so I can run CS6, but since the partition, the apps think they've been installed in a new set-up. Every time I try to launch an app (InDesign, Photoshop, Illustrator), my Adobe Application Manager pops up and asks me to sign in with my Adobe ID to use my "trial" version of the design suite. When I try to sign in, the "swirling ball" does its thing for a while, then I get a message that says I'm not connected to the internet or my computer clock is off--clearly both not being correct. 

A few issues: 1) When I initially tried launching one of the apps, I got a pop-up that wanted me to register (what I already have owned for...ten years?) or that there were zero days left in my trial. I clicked the trial button (thought it was some weird glitch), things launched, and I continued. Now, when I try to re-launch, there's my Adobe App Manager. 2) I have the physical CS3 materials, and believe the CS6 was a download, but is associated with an old (now non-existent) email (I believe). So, if I "un-installed" the apps from my partition, I have nothing to re-install. 3) When I look up the serial numbers of my products, it says they are already registered. I do have the suite installed on a laptop as well, and I'm unsure of how to "deactivate" things there, if that's the issue. 

I'm a retired graphic designer, need to access old files, create a few new ones, definitely don't need Creative Cloud services. Any help with this would be most appreciated. Tried phone support, but after four menus, I found that CS6 isn't "phone supported" anymore. I just need to have what's right here to work again. 

Thanks so much in advance.