Why are the edges of these two leaves burnt on the...

Sometimes a plant will just grow like that, maybe the leaf was damaged when it was very young and only now its grown out can the damage become visable, it could also be caused by a fan too close but I doubt that's the case with a plant so small.

Hello! Well....You fertilized on the first week, a very very bad ideea. Also the feeding chart must be wrong typed, Then 2nd week, You are using "Big Bloom", question mark. Reccomend to flush immediatly, then ph-ed plain water for 2 solid weeks. Then start with half of the reccomended dosage of the appropriate nutrient ;-) .

its definitely some mechanic damage during the development, as @Rap_a_cap said. the first few leaves often have some problems, just ignore it, your plant is healthy and safe <3

Hi mate, don't think its nutrient burn so it may be a PH issue. Hope this helps, good luck and happy growing