Here’s a really good write up about LED lighting. It’s easy to read and will give you the information you’re looking for.
It’s better to read it so you know how to adjust everything throughout the grow. You’ll get the answers your looking for in it.
This one first
https://www.reddit.com/r/HandsOnComplexity/comments/17nxpy/using_a_lux_meter_as_a_plant_light_meter/
Then delve into it more with this write up