Full backup, MacBook Pro 16", M2 chip.
It seems that my updated Sonoma is 14.3.1 is corrupted. Every time I go from one user to another everything is changed. Ten support wants to reinstall my OS system. Have a New Toshiba Portable Storage, 4TB. It's been formatted for MacBook Pro 17" vintage computer with El Capitan OS
10.11.6. I doin't want to use Time Machine.
How to do this backup?
MacBook Pro 16″, macOS 14.3