It's not a dumb question at all, and it's one that confuses a lot of people at first.
Paganism is an umbrella term that covers a wide variety of religions from Asatru to Zoroastrianism. It's hard to come up with a generic definition that covers all of those. Some...but not all...believe in the existence of many Gods and Goddesses. Some...but not all...are very in tune with the Earth beneath us. Some might describe them as any religion which is not Christianity, Islam, or Judaism.
Wicca is a very specific religion which falls under the general umbrella of Paganism. Wicca was introduced to the world in the 1940's and 1950's by Gerald Gardner. It has specific beliefs and practices that differ from those beliefs and practices of other Pagan religions.
It might be easiest to understand the concept if you think of the specific religions such as Asatru, Druidry, Wicca etc as being different denominations of Paganism.