Are sharks fish ?

Yes, they are cartilaginous fishes, meaning they have no bones. These were some of the earliest fishes to evolve in the oceans after jawless fishes. Most fish in the ocean today are bony fishes which actually evolved in fresh water and went back to the ocean.

They don't smell like fish. 

Are porpoises and dolphins fish?

Yes, "fish" covers a wide range of aquatic vertebrates, including the Chondrichthys, or cartilaginous fishes, which include the sharks.

No, they are wingless birds that live in the sea and breathe water

The short answer is Yes.