The Expo hunt runs throughout the Expo: from 14th February through 6th March.
Not all Exhibitors at the Expo take part in the hunt, but you can easily identify those who do by the 3D model of the expo logo that is rezzed on their store sign. There are no landmarks given for the hunt, so we simply advise you to TP to one of the sims and start exploring. Hunt items cost 10L each, with 100% donattion to RFL.
Hints are found here Be aware that the exhibitors aren’t required to give hints, so you won’t find a hint for every store.