How to adjust brightness on screen of my lenovo laptop. Have tried to use action centre but screen brightness will not work for me?

Depends upon the control keys of the keyboard on that model "lenovo laptop". With no clue which one you have, what control keys might be on it, no accurate guess can be made from far away.

If the fn keys don't work you need to go to the lenovo site and download chipset video. And
All other lenovo software and drivers for your machine your running on windows generic drivers that don't work!

Alternativly try the easy iobit driver booster and let it load and install all the drivers.

Uninstall it when done it is adware