If you are moving at a constant speed and changing direction, then your acceleration will not be zero. Acceleration is defined as the rate of change of velocity, which includes changes in both magnitude and direction.
Even though your speed may be constant, changing direction involves a change in velocity. Velocity is a vector quantity that includes both magnitude (speed) and direction. Therefore, if you're altering your direction of motion while maintaining a constant speed, your velocity is changing, and you are experiencing acceleration.
Acceleration can be calculated using the following formula:
Acceleration = (Change in Velocity) / (Time taken)
Since you're changing direction, the change in velocity is non-zero, and as a result, your acceleration will be non-zero as well.