1. Access the display settings window by right-clicking an empty space on the desktop background. You can also type “change display settings” in the search bar and press enter.
2. Click on the drop down window under Multiple displays and choose between Duplicate these displays, Extend these displays, Show only on 1, and Show only on 2. (Keyboard short-cut for display settings are Windows + P)

Windows + P

• PC screen only — Only the primary monitor is used.
• Duplicate — Secondary monitor shows duplicate desktop.
• Extend — Both monitors combine to offer an extended desktop.
• Second screen only — Only the secondary monitor is used.

3. If you have more than two monitors, you have the option of duplicating two of them. The settings can be changed under Multiple displays. (i.e. show on 1 and 3, 1 and 2, or 2 and 3) This will allow you to mirror two of the three displays.
4. You can rearrange the display windows by clicking and dragging them to control how the mouse will transition to the other displays.

https://www.windowscentral.com/how-connect-and-set-multiple-monitors-windows-10