Tape a square (roughly 12"×12") on the floor with masking tape. Hand the child a ball or a rolled-up sock.
Stand back a few feet. Bounce the ball once so it lands inside the square. Look pleased.
Aiming, missing, adjusting. The child will quickly invent variations: bouncing off the wall, dropping from above, sitting and rolling, two squares at once.
Make a "miss zone" with a second tape color. Tape three squares of decreasing size for a difficulty ladder. Number the squares and call them out as "tonight's target."