That's a standard message if, for example, the battery's been disconnected for some reason. It means the unit needs the anti-theft code. The original unit in the SE trim has a fairly prominent power button above the top right corner of the screen (it's a physical button, not a virtual one). For the "colour display system" fitted in the base "S" trim level, you press the volume knob. A long press forces the unit to get the anti-theft code from the car's ECU and enables it to restart.
But your comment seems to suggest the car doesn't have the original infotainment unit; have you or a previous owner replaced it? If so .... no idea I'm afraid. There must be some way of inputting a radio code, you'll need to find the code and the instructions for that unit.
