The clock screen will show the current time.
It will display an 'A' for AM or a 'P' for PM provided the clock is set in 12Hr mode. See how to set the clock.
The little person in the lower left corner indicates the step sensor is ON. See how to Activate / disable the step sensor
The pedometer is designed to have the screen on all the time, it won't use any more power than a digital watch when idle.
To advance from one screen to the next, press the MODE button.