yellow leaf

Absolutely normal...........first grow??

Plants will shed their old leaves they are not longer using or want to get rid of. That was its its first set of true leaves that had 1 finger. I would not worry about it.

if it is isolated, i'd ignore it. That's a single-bladed leaf - the 2nd set the plant grew, i.e. one of the oldest leaves and not even a mature leaf for lack of the proper vocabulary. These often get shed, like cotyledons, by the plant and no other symptoms will be seen. If it is progressing anywhere else, take a different approach. From what i see, the other foliage is healthy and a uniform shade of green. Let it suck it down until a very gentle tug causes it to fall off. Do remove from growing area. Decaying leaves are a disease vector long-term... no worries letting the plant suck it down, though. 23 days with side branching as thick as that, secondary branching off that, too? think this is measuring from the taint, lol. The others look closer to what should be.