Robin is right. the orange symbol is a snowflake indicating freezing conditions. If your car is like my 02, you might try hitting the reset button (see below) to get rid of it.
About the trip computer; if your dash is like mine, the control buttons are on the side panel under the headlight switch. Left to right is the button for switching from A to B, the reset button and the button for switching from Km to Miles and back.
When the Trip button (on the end of the left stalk) is pressed, you may cycle through the readings for either the A or B channel of the trip computer. When one channel is selected, pressing the A/B button selects the other channel. If you press and release the reset button, the display reverts back to the odometer. If you press and hold the reset button when one channel is displayed, that channel will be reset. When the display is just showing the odometer reading the buttons are not active.
If you have any other questions I’d be happy to answer them.