Yellow tips and brown spots

I found that before they get the full 3 set of leaves, they do weird shit and you shouldn't worry too much about it. I'd really only worry about it being too lanky, or too small, yours looks fine for 2 weeks

It was probably starving of nutrients and since you transplanted it, now it’s able to uptake what it needs. Keep the soil moist and water as needed. Water enough to saturate the entire pot all the way through and have roughly 10% of water come out the bottom every time. Never water in only one place.

Give it time. Too young to tell

I think it needs more time. If the soil has nutrients in it then that's a bonus and it needs time to explore and get em. If its still yellowing and progressing further it might need a bit more instant feed, something like a 4-6-8 liquid or equivalent till the microbs breakdown the soil a bit more if your using dry amendments in it. If its liquid feed then follow the direction on the bottole for the stage of lifes its in and be catious of overfeeding em. Good Luck!