iCloud ruined my MacBook

Open system preferences > iCloud and uncheck the box of iCloud Drive a pop up window appears , showing to keep a copy of documents , and remove from the Mac .

( a ) if you had clicked on keep a copy , they will be archived in home folder that can be viewed by clicking on finder in the dock , take cursor on top menu bar > Go > Home > your user name > iCloud Drive ( Archive ) .

Note : you have practice of always unchecking the box of iCloud Drive and keeping them locally , however you had not planned to increase the storage plan , when iCloud Drive and desktops and documents was turned as on the extra documents didn't adjusted in iCloud server and were mot saved , however if you followed these steps some are still iCloud Drive ( archive ) folder .

And again you open system preferences > iCloud the Apple ID icon doesn’t not exist , click on sign in with your original Apple ID and password .

It will prompt to enter Apple ID , click on next and password , again click on next , a red notification will appear over the system preferences , and the icon starts bouncing .

Enter the admin password and click on ok .

It will prompt to enter Apple ID , click on next and password , again click on next , a red notification will appear over the system preferences , and the icon starts bouncing .

Enter the admin password and click on ok .

A small circle will be rotating in front of Apple ID field .

It will prompt to merge contacts , calendars …click on merge .

In front of iCloud Drive - options check the box of desktops and documents a small circle will rotate , setting up and finally the box will get checked .

The box of keychain is unchecked , tap the box it will be semi greyed for a short while but get checked completely in few moments .

See the articles https://support.apple.com/en-us/HT201318

https://support.apple.com/en-in/guide/mac-help/mchle5a61431/10.14/mac/10.14

For Mac OS catalina 10.15.6

Open system preferences , click on Apple ID icon .

Click on overview in the side bar and click on sign out .

Click on keep a copy .

In the next upcoming pop up , click on keep on this Mac .

Enter the Apple ID and password and click on continue .

The Apple ID is completely removed .

If you again check the box of iCloud Drive it will show setting up the documents that are saved in iCloud will sync , folders are not saved in iCloud.com , regarding photos if you always have synced with icloud , after sign in with apple id and password , click on photo application > click on continue and follow these articles https://support.apple.com/en-in/HT204264

https://support.apple.com/en-in/guide/photos/pht5156cc968/mac

About plugins see https://support.apple.com/en-euro/guide/safari/ibrw1036/13.0/mac/10.15