I don't understand normal type. It seems like a Pokémon is "normal"type if it's not anything else (fire, grass etc)
So if that is the case, shouldn't all pure types be part normal?

Let's say you have a dragon, and we let it it fly. Dragon/Flying. Or, we make it a ghost: Dragon/Ghost. But what if we add nothing special to it? It stays "Dragon", while it's actually a normal dragon.

Also, why doesn't normal just have nothing special to it? 1x damage from everything, 1x damage to everything