How to adjust the brightness on the Lenovo laptop the brightness seems to be all the way up high?

If it's a laptop, then there's a battery life icon in the bottom left corner. Click on it and you should have the option "Adjust screen brightness"

Assuming its a windows operating system within 5 years fn along with f5 and f6 for lower and higher
If not f5 and f6 then look for flowers in tv screens or light bulbs on f keys at the top then fn and the respective key.