You can ask Apple to request access to the Apple ID account: this would cover photos stored in iCloud, Calendar, Contacts, email and any documents in iCloud Drive.

https://support.apple.com/en-gb/HT208510

It is possible to reset the disk password, by booting into Recovery mode, selecting the Terminal app, and typing resetpassword.
https://support.apple.com/en-gb/HT212190

It may also be possible to reset the password using the AppleID.
https://support.apple.com/en-gb/HT202860

Alternatively, if the data is not encrypted on the disk, then you might be able to access the files using Target Disk Mode. This treats the Mac like an external disk for another Mac. Connect the two computers with a cable, and boot the target Mac while holding T.

https://support.apple.com/en-gb/guide/mac-help/mchlp1443/mac

You should be able to access all the files and folders.

You could also check if there is a backup disk that isn’t password protected.