how do i enter command prompts
 

im having trouble installing software on mandriva i have read various tutorials and they all go on about entering codes and stuff but i dont have a clue where to enter them .... can any one help ?

If you have a GUI, you can run something called a 'shell' (see if there are any strange icons suggesting that). If yo uhave a GUI but can't locate the icon or menu item to start a shell, press [ctl][alt][F1] to get Virtual Console #1. Log in there and type your stuff. If you type 'exit' after all the other stuff, you should be dumped back into the GUI; otherwise press [alt][F7] to switch back to the GUI. Don't leave anyone logged in on the virtual console when you're not using it, especially not 'root'.

Also look for "Terminal" or "Konsole" in your menus.

Try
right click (desktop) -> terminal (or Konsole)