u/Iaquobe

I'm having so much trouble getting out of the seedling stage. I tried a few growths, but at some point in the first weeks my plants turn yellow and die. I tried watering more and watering less, and still they turn yellow and die.

Here are my current three plants. In the first pic its the first day in their new pots, and the second is 2 days later (now). I suppose they don't look too bad right now, but already the new growth is turning yellow and I'm afraid it will get worse again.

What should I do? Have I overwatered/underwatered them? Is the light too close/far? Should I even try to correct something, or should I let them do their thing?