Attached a small demonstrator program.
It is a B4XPages project, tested with B4J, B4A and B4i.
The field is scaled and the cursor positions are displayed at the bottom of the screen.
The field dimensions are taken from
HERE, in meters.
The goal is zoomed by a factor of 4, hard coded.
When the cursor is in the goal field, the position values are those of the goal.
The x positions are referenced to the middle of the field.
When you touch the screen, a cursor as a cross is displayed.
Be aware that the cursor is above the touch point of the finger to make the cursor visible, this displacement is defined with the variable DeltaFinger.
When you press the Shot button, and touch the screen, the cursor is a circle. You can move the cursor.
The cursor appears only in the field.
When you release the finger the last position is memorized and this first point remains displayed
Then, when you touch the screen again, the cursor appears only in the goal area, you must move the finger to be sure that the cursor is in the goal area.
When you release the finger, the shot is displayed in blue and the shot is added to a list.
Then, you can repeat the operation again.
Press the Clear button, the display it cleared.
Press the Draw button, the shots are displayed again.
Press the Clear shots button to clear the shots list.
You need to adapt it to your needs.
It is a demonstrator project, not optimized, with probably some bugs and some debug and testing code.