How to Create Partitions in macOS
As with most things in macOS, it’s dead simple. You can, of course, do this from the Terminal, but we are not gonna go there today. To create a simple partition, we are going to use Disk Utility, which you can find in the Finder > Applications > Utilities folder; or just press Command + Spacebar then type Disk Utility.
Select the drive you want to edit within the sidebar, then click the Partition button.
Select the slider on the pie chart, then drag it until the desired size is reached. Click Apply to confirm changes.
Wait while changes are applied.
Proceed to label the drive.