You are currently accelerating at 1g towards the Earth’s center of mass. The ground obviously prevents your fall, but you feel the acceleration as your weight.

The ‘g’ in 1.5g refers to acceleration of Earth’s gravity at the Earth’s surface, 9.8 m/s/s. Obviously, if the ride moves you it accelerates you, but slightly less obvious is that changing your direction (like swinging you in a circle, instead of allowing you to follow a straight line), also accelerates you. Consider the “Turkish Twist” ride where you stand in a large cylinder that spins. You experience a force that holds you against the wall. If you were on the outside, the spinning would throw you off in a straight line tangent to the cylinder. Inside, however, the wall is restraining you, pushing you onto the circular trajectory, accelerating towards the center of the circle at a rate proportional to the rotational velocity of the cylinder (you are experiencing acceleration even if the cylinder is rotating at a constant velocity). You are accelerating because your velocity (speed and direction of movement) are changing.