Divorced Catholics are full members of the Catholic Church and are invited to participate fully in the life of the Church.
There are no laws preventing a divorced Catholic who has not remarried from active participation within a parish. This includes receiving Eucharist and Reconciliation, or participating as a Lector, Eucharistic Minster, Parish Council member, etc. You do not need absolution prior to fully participating.
Pope John Paul II encouraged Bishops to stress to the clergy of each diocese the need to reach out to divorced individuals and to remarried couples (Familiaris Consortio, #83 & #84). Parishes are to include them in parish participation.
A Catholic who divorces and remarries without an annulment is considered to be in an irregular marriage and is not open to receive the Eucharist. But these individuals, too, are considered full members of the Catholic Church and are invited to participate in the life of the Church.
From Declaring a Marriage Null, p.3, Archdiocese of Anchorage:
Catholics who are divorced but who have not entered another civil marriage are encouraged to practice their faith fully, including participating in the sacraments. Merely being separated or divorced does not change one’s status in the church. Divorced Catholics are full members of the church with all of the same rights as any other member. Catholics who are divorced and who have remarried, without a declaration of nullity, are not free to receive the sacraments, but are encouraged to practice the other aspects of their faith, pending a decision by the tribunal regarding their former marriage.
From Follow the Way of Love: A Pastoral Message of the U.S. Catholic Bishops to Families On the Occasion of the United Nations 1994 International Year of the Family, United States Conference of Catholic Bishops, September 1993:
Divorced and widowed persons: relationships and circumstances within your family may have changed, but God's love for you is ever present and does not come to an end. Grasp the hands of those who reach out to you in loving concern. Extend your own hand to others whom you meet on the road to healing and reconciliation. There is a home for you within our parishes and communities of faith.