Turn off the laptop and unplug it
Check whether the black spots appear in screenshots
If the spots appear in screenshots, update or reinstall the graphics driver
If the spots do not appear in screenshots, the screen panel is likely damaged
Gently clean the screen with a microfiber cloth
Use a screen-safe cleaner only if needed
Check for pressure damage or cracks on the display
Connect an external monitor to confirm whether the issue is with the screen
Reseat the display cable if you are comfortable opening the laptop
Replace the LCD panel if the black spots are permanent
Take the laptop to a repair technician if the damage is internal