I would recommend getting some shade cloth so you don't have to move the plants. I just lay it over them in the hottest part of the day
So I have 2 sections of lights, a 2ft section and a 4ft section. 6 rows of lights. I stated out with 6, but found quickly that it was far too much for my seedlings. So I halved it and moved my lights as high as they go. In this picture they're probably 18-22inches above the tops of the seedlings, but right now I have so many seedlings that some are stacked and super close to the lights lol.
These are the lights that I'm using:
https://smile.amazon.com/gp/product/B082ZL1Q63/ref=ppx\_yo\_dt\_b\_asin\_title\_o07\_s00?ie=UTF8&psc=1