The English word "Easter" is not a biblical word. It is thought to be a translation of the name of the Anglo-Saxon spring goddess, "Eostre". In any case, it is an English word which is used today to translate the Greek term 'Pascha', which translates the Hebrew term for 'Passover'. The Christian Church transformed the Jewish Passover, which commemorated the freeing of the Hebrew people from Egyptian bondage into a feast which commemorated the death and resurrection of Christ which freed humanity from the bondage of death, sin and evil.
We do not have a command from Jesus to celebrate the Paschal Feast. But the Bible clearly indicates the New Testament belief that Christ is the New Pascha for believers in Him, and that this is to be celebrated by Christians:
"For Christ, our paschal lamb, has been sacrificed. Let us therefore celebrate the festival ..." (1 Corinthians 5:7).
Thus the celebration of Christ's Resurrection became the first Christian Feast - the Christian Pascha.