ninjaphrodite wrote:
I’ll get a compatible MacBook for this. I’d like to make sure my external backup, Time Machine & photos are accessible from Windows or Linux in the future, so they need to reformatted as ExFAT, right?
If you are talking about a directly-attached backup drive, Time Machine backups should not be stored on an exFAT-formatted drive. APFS or HFS+ (Mac OS Exetended) only, with APFS being the preferred format.
Types of disks you can use with Time Machine on Mac - Apple Support
No matter where you store Time Machine backups, Time Machine is not the backup application to use if your intention is to pick apart those backups using Windows or Linux. A Time Machine backup is best treated as a "sealed box" that should only be accessed via Time Machine – which only runs on Macs.
Carbon Copy Cloner and SuperDuper! are clone backup programs, so if you made backups using one of those, you'd have an easier time picking through the backup on Windows or Linux. You still might want to use APFS or HFS+ for the format of the backup disk. I'm not sure whether certain programs like Photos like having their databases stored on any sort of Windows-formatted volume.