Did I do wrong?

Yea dude slow your role... It's a common mistake amongst new growers to think they can "force" plants to grow faster or stronger.. There is nothing you can as a newbie that will guarantee success.. Other then maybe being patient and allowing your plant to grow.. Be patient.

The roots coming out of the stem you will discover more often in the future. Don't cut them. Plants that small you never ever will need to cut anything. They are really vulnerable when they are seedlings.

bro if you want good weed and good buds later with this plant stop messing with it. the plant was breed to do certain things in its life, by cutting and messing around you may lose a harvest later. i recommend just let the plant be so you can see how the plant grows and learn how it grows, you will have a good harvest each time. cannabis can take a lot, the only thing you need to do is give it food and water, light and air. so just sit back and let the plant be. i promise you that it will all turn out the way it should