The first Elf awakened at Cuiviénen in Tolkien’s legendarium is Imin.
According to the creation history told in The Silmarillion, the first Elves awaken beside the waters of Cuiviénen under the stars. Imin is described as the first to awaken, followed by his partner Iminyë. He is later joined by Tata and Enel, who awaken groups of additional Elves.
These early Elves form the first clans and eventually encounter the Valar’s messengers. The invitation to travel west leads to the Great Journey, although not every Elf accepts it or completes it. The groups that begin this history become associated with later divisions among the Elves.
Imin is easy to confuse with major Elven leaders such as Ingwë, Finwë, and Elwë. Those figures become important in later migrations and kingdoms, whereas Imin belongs to the earliest awakening tradition at Cuiviénen.