Connect accessories to your Mac mini
Plug in a compatible keyboard, mouse, trackpad, or other optional device to start using Mac mini. You also need to connect a display when you first set up Mac mini (see Connect a display to Mac mini for details).
You can also work wirelessly using Bluetooth® technology. Your Mac mini can connect to optional wireless devices such as Magic Keyboard, Magic Mouse, Magic Trackpad, AirPods, peripheral devices, and wearable sport accessories.
Accessories are sold separately at apple.com, your local Apple Store, or other resellers.
Connect a Bluetooth device. Turn on the device so that it’s discoverable, then open System Preferences and click Bluetooth. Select the device in the list, then click Connect. The device remains connected until you remove it. Control-click a device name to remove it.
Turn Bluetooth on or off. Click the Control Center icon 
in the menu bar, click the Bluetooth icon 
, then click the control to turn Bluetooth on or off. Your Mac mini comes with Bluetooth turned on.
Learn more. See Use Bluetooth devices with Mac in the macOS User Guide.