Read my Ssd from my MacBook Pro retina mid 2012

You can try putting the old laptop into Target Disk Mode so that the laptop acts like an external drive.

You can purchase an OWC Envoy Pro Enclosure to install an Apple original PCIe SSD to use as an external drive (sometimes they offer used or open box items at a lower price).

https://eshop.macsales.com/search/?q=envoy%20pro%20enclosure&filter.catidpath=4353&filter.dimension_type_135=Bare%20Enclosure%20Only

You should always have frequent and regular backups. FYI it is impossible to recover accidentally deleted data from an SSD after the Trash has been emptied plus an SSD can fail at any time without any warning signs. With later USB-C Macs it may be impossible to recover any data from the SSD if the system has a hardware failure (especially for systems with a T2 chip or an M1 Mac). macOS includes Time Machine for free so users can back up there Macs.

The SSD you are attempting to access uses the new APFS file system that was introduced in macOS 10.13 High Sierra so older versions of macOS are unable to access the APFS file system (except for macOS 10.12.6 which can mount & read APFS).

It gets even more complicated since the SSD was using macOS 10.15 Catalina where Apple modified the volume layout separating out the OS system files and user data so these two volumes get mounted separately. I believe you need to access the user folder(s) from "/Volumes/Data". Keep in mind both the "Macintosh HD" & "Macintosh HD - Data" volume will have a "/Users" folder, but only the one on "Data" will contain actual user data.

Have you tried booting into Safe Mode on the Retina 2012? You really didn't explain the exact details of the issue with the Retina 2012 laptop.