This is the simplest answer for this series. The crucifer has one official duty—to bear the cross in the processions.
In many places the crucifer also acts as something of a team leader for the acolyte team. The one chose to bear the cross is often a senior or experienced acolyte and known to be responsible for leading the procession into the church, placing the processional cross where it rests during the service, and directing the acolytes in their various roles during the service so the Presider and assisting clergy, can perform their tasks uninterrupted.
The role of the processional leader brings to mind the whole issue of processionals. Many churches not in the boarder Catholic traditions (i.e., the Roman Catholic Church, the churches of the Anglican Communion, and the various ethnic Orthodox Churches, of the Chalcedonian and non-Chalcedonian variety) do not have processionals. They begin their services in other ways. Additionally, the BCP does not require a processional, except in the Liturgy of the Palms. Processions are also expected, though not required, in a burial service. During COVID lockdown and in this period just following post-COVID lockdown, St. Francis has eschewed processions outside of Holy Week and Easter. It is not that we do not like processions, we are only now approaching the attendance levels that make processions special and we are also only now beginning to source those ministries which make present the processional as fulsome (i.e., with a lot of people in it).
At the front of all these processional moments are crucifers, who pace the speed of the procession, add dignity and gravitas to its action, and who bear the symbol most associated with Christianity—the cross. Should you be interested in this ministry, the people to contact are the Rector at email@example.com or at 703-759-2082, ext. 102, the Parish Administrator at firstname.lastname@example.org or at 703-759-2082, ext. 101; or the Acolyte Coordinator, David Black at email@example.com. There is some training and knowledge that go with this role, especially because Crucifers are able to assist younger acolytes and other ministers of the altar. You are encouraged to reach out, ask questions, and help lead our Eucharistic celebration.