Paganism is very broad and has no set definition. I theorise there being 2 spectrums of paganism.
1. Tendency (e.i Celtic, Wiccan, Norse, Druid, Christo', Islamo')
2. Belief (Cultural, literal, Metaphorical, spiritual, pantheist)
Example:
Cultural Norse, Spiritual Druid etc.
Note that paganism is not inherently the belief in many gods, most neo-pagans are not literal pagans.
Btw I am a materialist-atheist. I only follow the year-wheel of the pagans not the religion.