Sunday, May 1 is Lei Day in Hawaii.
Kapiolani Park in Waikiki has a really nice Lei Day celebration.
It is free.
Several musicians/groups, craft exhibitions & food booths.
You will see some really beautiful lei.
May 1 is also Malasada Day. So load up on the malasadas from Leonard's or other bakery that makes malasadas.
Also see note about May 2 at Kawaiaha`o Church on the above link.