Hello and welcome.
Event rares are gotten by decoding the clues found
here, then when you find the star Eater you give him the required number of stars. Stars are earned by posting in the event forum, .25 of a star per post made in a thread you did not create, or .10 of a star when someone posts in a thread you made.
Tokens for the event commons are earned by visiting Dance, Feast or Song and petitioning them. Links to their profiles are in the thread I linked above.
Edit: Hmm it seems you can earn stars for posting in any forum that grants gold for posts.. I thought it was just the event forum posts that gave stars.