Swinging through forehand question

How do you exactly swing through a forehand? I feel I’m able to do it well in mini tennis, but once I go to the baseline I start struggling to hit with depth or even engaging my legs for it. I also noticed my weight transfer goes from down->up rather than right->left or back->front which causes heavy topspin, but often lands short around the service box. I also don’t remember being able to see the ball get hit anymore unlike in mini tennis, but idk if that’s because of the increased speed of the ball or because I’m moving too soon.