Hey Demir!
I’ve had a look at the clips and I would say the main things to work on are keeping relaxed but compact strokes, your forehand tends to finish across your body instead of in front of you. This usually happens because there isn’t enough backswing, so give that a try. Also being sure to keep the shot hinging from the elbow and not using to much shoulder.
I think if you can get a good foundation of basic shots there is a lot of potential to improve. So spending time really working kn having solid technical shots. The main area to focus on is the videos in the basics section on the Academy, this is the solid foundation that will help you improve.
I would also say working on being lower and with your weight more forwards from the clips I have seen there, especially as you seem quite tall. This will really help with movement and getting into position for each shot.
