Dual booting Mid 2012 MacBook Pro running Catalina with Deepin

After the Catalina upgrade Macintosh HD is listed twice in Disk Utility. One only has about 10gb used and the other looks like that's where everything is. It has the label data in the name. I read somewhere that this is normal. I want to dual boot linux, thinking about Deepin, and need to create the install partition. How exactly should I proceed?

It's quite straightforward, but when playing with partitions and dual boot systems, things can go wrong so:

• First use CarbonCopyCloner to make a clone of your Mac in case anything goes awry.
• Next, reboot the mac and hold down Command-R as it's restarting (when you here the gong usually) to boot into recovery mode.
• Once recovery mode boots up, select Disk Utility and repartition the main disk (select the top disk (usually) and click the partition icon)
• It will ask if you want to add a volume (which is what the 'data' volume is) or Partition, choose Partition.
• Change the existing partition size to make room for the new one and Apply.

Now you have room for the Linux Boot Partition, simply follow the instructions at:

https://www.techonia.com/6156/install-manjaro-deepin-on-macbook-pro