I don't see any light burn. Those all look very healthy.
The next few weeks of your grow is where I ALWAYS have problems.
Go buy some mosquito bits. Soak about 2 tablespoons in water, and use that to water with. It has a bacteria that likes to eat fungus gnat larvae.
Don't over water. This is the hardest part about growing in soil / peat moss for me, is in the next few weeks you can easily over water and make the plants sick. Be diligent about your water.