There's a huge number of gods out there from a huge number of different cultures (celtic, hellenic, aztec, egyptian, polynesian, roman, germanic, native american, moari, japanese, chinese, hindu, persian, carthaginian, scythian, incan, mayan, african, slavic, and thats all I can think of off the top of my head). I'd pick a culture you like, or even a culture at random and read up on its mythology.
Some gods seem familar and are easy to understand:

Ares, Hellenic God of War. Easy enough

Quetzalcoatl, Aztec god who gave mankind books and...maize?! Also this picture depicts the god in"human" form!
However I am not a Wiccan, so I'm not exactly sure how multiple gods of multiple cultures fit in