[Az-Geocaching] Question about Event Caching

Can someone tell me in 25 words or less how to set up an Even Cache?? I
have seen several posted in different places and the couple that are
near me are on days when I have something else going. Trisha told me
one time that if I wanted an Even Cache at a time when I could get there
was to plan one myself. I just don't have any idea what is involved.

Thank you, Bob Smith, Team Petite Elite