The Vocation to the Single Life is sometimes portrayed as the vocation of default. That risks missing its importance as well as the thought and prayer of many who follow this way of life.
We all enter adult life in the single state, but most do not spend their entire life in it. Most people will discern a calling to another pathway that they then commit their life to. For most Catholics in early adulthood, the sensible approach they take with life is simply to get on with it, aiming to lead a constructive Christian life. However, over time it may become apparent either through circumstances as they emerge during life or via a calling that is detected, to spend one's life in the single state is the best path - a means to live a life of value and purpose growing in love of God and being of service to people. In whichever way people find this path, it gives them a chance to commit to looking at the gifts they have and how they can use them and the opportunities that come with living as a single person to act in service to society as fully as they can. Single life is also likely to grant them the time to better develop a spiritual life so that they can come to know the love and care of God in their life. The vocation to the single life is one of immense value to the Church and society as a whole, and is lived out by many outstanding Christian people.
In considering the vocation to the single life, you may find the following reading of use:
Single for a Greater Purpose - A Hidden Joy in the Catholic Church, by Luanne Zurlo, Published 2019 by Sophia Institute Press, 185 pages, ISBN 1622826566
Single and Catholic, by Judy Keane, Published 2016 by Sophia Institute Press, 127 pages, ISBN 9781622822409