The oldest volcano is Kohala then Mauna Kea, Hualalai, Mauna Loa which is still active, and Kilauea with is also still active. There is a sixth volcano called Loihi. Loihi is still forming under water off the coast of the big Island. There are many different stages in which volcanoes form. There are also many different types of volcanoes.
Volcanoes form in nine different stages.
If you look at the above animation you will see the nine main stages. Kohala Kohala is the oldest of the five main volcanoes. It erupted 60,000 years ago. Kohala is at its final stage in growth. Today Kohala is extinct.