anyone who is good at physics here?i need help fam

Spinning of the object does cause a change in position therefore it is considered motion and a object moving free in space and spinning will experience 3 forces instead of two i can draw you a rough representation of the basketball's parabolic motion and we see that the ball will fail to move straight forward rather it will be in a curved motion. affected by the downward pull of gravity and the spinning force dependant upon the direction of spin.

how does spinning a basketball affect its motion?( how does this even increase the downward force acting on the ball?)

What is a 'spinning force'?

Aerodynamics. If the ball is moving through the air, then the relative speed between the surface of the ball and the air will be different on the different sides (as defined by the axis of rotation and direction of travel) of the ball. Applying Bernoulli's principle, you will get a pressure difference, which will alter the trajectory.

how does spinning a basketball affect its motion?( how does this even increase the downward force acting on the ball?)

Spinning of the object does cause a change in position therefore it is considered motion and a object moving free in space and spinning will experience 3 forces instead of two i can draw you a rough representation of the basketball's parabolic motion and we see that the ball will fail to move straight forward rather it will be in a curved motion. affected by the downward pull of gravity and the spinning force dependant upon the direction of spin.

Basically, if you throw a ball forward through the air so that it makes a parabola, the air will move in the opposite direction to the ball itself (assuming that the ball isn't moving, you could say that the ball has a repulsive force acting on it which is the air resistance). If you spin the ball backwards when you toss it forwards, the top of the ball will make it easy for air in contact with the top to move around it and down. The bottom will thus be moving in the direction opposite to the air's resistance, so the air movement is restricted there.
Because of this, the downwards movement of the air via the top of the backwards spinning ball will act as another contributing factor to the ball accelerating downwards (aside from mg).

It is the opposite case if the ball were spinning forwards - it would accelerate to the ground more slowly as there is now and upwards force acting on it.