How to back up two Macs without over-riding the most current files
I recently purchased a new Mac laptop as my other was being repaired. Now I have the repaired one back. How do I update that one and keep backups with my new laptop as the primary. I'm concerned that the older Mac will over-write my new one.
I have an external hard drive which I use and I back up to iCloud (of course) and Google drive.
Thank you - Claire
MacBook Air 13″, macOS 10.15