how to get my starting again?

i have a 1999 v reg renault clio which is showing a fault light warning on my dashboard the car wont start and when it does it cuts out straight away or when i brake i have to rev the car so it wont stall, i recently bought the car and it had no service history what so ever. Im sure its the engine fault warning light thats showing what can this be and how do i sort the problem out as i need the car for my disabled son