I know that the Valance number is 2 and the unpaired electrons are 0
Unfortunately you are incorrect.
Think about the electronic structure of the carbon atom - what is the electron configuration? For example, fluorine is 1s
22s
22p
5.
The valence electrons are the electrons that are involved in bonding to other atoms. These are in the higher energy shells (usually only the outermost shell - sometimes called the valence shell).
The core electrons are those that are not involved in bonding (these are in the lower energy shells close to the nucleus - hence "core").
Have another shot at it and see what you come up with...