How do I free up or add space on my Mac mini?
How do I free up or add space to this mini?
[Re-Titled by Moderator]
Cafe to tell us what model / year of Mac mini "this" is?
We can't see your Mac, so we don't know what you have exactly.
Check Apple Menu ➜ About This Mac for that info.
With that said, to free up space, you need to delete files and content you may no longer need, or move them out to an external drive.
click here ➜ Free up storage space on Mac - Apple Support
Depending on the model / year of the Mac mini, you may or may not be able to increase the onboard storage on it.
You can always connect external drives to it to have more storage for files and data.
click here ➜ Connect and use other storage devices with Mac - Apple Support