Poʻe means people, persons, even an entire population. The Hawaiian people are called ka poʻe Hawaiʻi. Poʻe can also be used as a plural marker when talking about people, as in kaʻu poʻe keiki —my children.
Inoa means name. Koʻu inoa means “my name,” kou inoa means “your name.” So the next time you hear someone ask, “ ‘O wai kou inoa?” Just tell them what your name is.