The days of Lent are the final Period of Purification and Enlightenment leading up to the Easter Vigil. Lent is a period of preparation marked by prayer, study, and spiritual direction for the Elect, and prayers for them by the parish communities. The Celebration of the Sacraments of Initiation takes place during the Easter Vigil Liturgy on Holy Saturday when the Elect receives the sacraments of Baptism, Confirmation and Holy Eucharist. Now the person is fully initiated into the Catholic Church.
As a newly initiated Catholic, they continue their formation and education continue in the Period of the Post Baptismal Catechesis, which is also called Mystagogy. This period continues at least until Pentecost. During the period the newly baptized members reflect on their experiences at the Easter Vigil and continue to learn more about the Scriptures, the Sacraments, and the teachings of the Catholic Church. In addition they reflect on how they will serve Christ and help in the Church's mission and outreach activities.
The newly baptized are dressed in a white garment after baptism to symbolize that they are washed clean of sin and that they are called to continue to walk in this newness of life.
SOURCE FOR THIS Q&A: USCCB.org/beliefs-and-teachings/who-we-teach/rite-of-christian-initiation-of-adults/