Additionally, you need to take care on many other road user, cause pedestrians and bicycle drivers, who are crossing the street parallel to you, have priority. Opposing traffic has also priority, you need to take note of them and let them go first. Especially turning left, it is difficult to place your car right. 50 centimeters to much left or ahead means, that you place your car in the opposing traffic.
It is very important to prepare early enough for turning, to consider all possibilities and take the right gear. That necessitates much practice. You need to understand the explanations of your instructor.