Plug any generic code reader into the socket that is hidden behind the panel by your right knee. Couple of cross head screws to remove the panel, I think.
The code reader above will give you the codes and reset the light (but not much else). Might even be cheaper to get a phone app and one of the blue tooth things. Sure they're less than a tenner.
Can't really make any judgement about fault without a code or description of symptoms. Does it drive ok? If you have a multimeter you could check the battery, as a weak battery can sometimes give spurious fault codes.