Question

if energy can neither be created nor be destroyed so why are we worried about our energy resources

Answer 1

We are worried because we don't have more of fossil fuels to burns and get energy from it, the statement of energy conservation is true but if we can't convert the energy to a form we can use, then it's a sure problem.

Answer 2

Energy resoures are those resources which can't be renewed by any physical or chemical methods
These resources cant be recreated at all
so we should minimise their usage and it takes million of years in formation