It's not a "dumb question"! There are so many different spiritual systems covered by the term "Pagan" I sometimes have difficulty in keeping track of them myself. The quick answer is "All Druids are Pagans, but not all Pagans are Druids" for a more in-depth answer I have found a good reference/starting point
here .
Druidic beliefs are remarkably flexible, and while the most popular system is still
Celtic Druidry , there are new expressions developing all the time. A good example of this are the
Star Trek Druids who have a grove in my local area of Portsmouth UK