NEW: Vatican: Benedict slept well and is spending his first day in retirement reading and praying The cardinals are summoned to a first meeting on Monday morning Rome (CNN) -- With the dust still settling from Benedict XVI's historic resignation as pope, the focus in Rome turns to the future Friday as Roman Catholic cardinals prepare to meet to discuss a timetable for picking the new pontiff. A letter issued by the dean of the College of Cardinals on Friday calls the cardinals to come together Monday morning for the first in a series of meetings, known as general congregations. There will be a second session Monday afternoon, according to the letter from Cardinal Angelo Sodano. One of the cardinals' first tasks will be agreeing a date for the secret election, or conclave, in which they will pick Benedict's successor. However, the date for the conclave may not be set Monday, Vatican spokesman the Rev. Federico Lombardi said Friday. The cardinals will also hold important discussions on the future direction of the church, which has been beset by scandal in recent years, and the kind of leader they want to see at the helm. All the cardinals attend the general congregations, but only cardinals who are younger than 80 are eligible to vote for the new pope in the conclave. They are expected to number 115, the Vatican has said. How many cardinals are now gathered in Rome is not yet known, Lombardi said. Quiet life Benedict, meanwhile, has embarked on the first day of his new life of seclusion following his televised departure from Vatican City on Thursday. Benedict, who will now be known as pontiff emeritus, will spend the next few weeks at the papal summer residence, Castel Gandolfo, before moving to a small monastery within the Vatican grounds. After his resignation took effect Thursday night, he had a good dinner, watched Italian TV newscasts about his last day, performed his regular evening prayers and read messages sent to him about his retirement, according to the Rev. Thomas Rosica, another Vatican spokesman. The pope emeritus also went for an after-dinner walk in the corridors of the centuries-old Castel Gandolfo, sited on a quiet hilltop overlooking a lake. Benedict XVI slept well, Rosica said, citing his personal secretary, Georg Gaenswein. In the weeks leading up to his retirement, the pope played piano every night after dinner, but didn't on the night of his retirement because he was watching TV, Rosica said, citing Gaenswein. The pope emeritus brought several books of theology and church history to Castel Gandolfo, the spokesman said. He is also expected to resume playing the piano after dinner. On Friday, he celebrated morning Mass and will spend time in the Castel Gandolfo gardens, saying the rosary. Just a pilgrim Benedict's final public words were given to about 10,000 people who had gathered at Castel Gandolfo to bid him an emotional farewell. I am no longer the pope, but I am still in the church. I would still -- with my heart, with my love, with my prayers, with my reflection and with all my inner strength -- like to work for the common good and the good of the church and of humanity. He is the first pope to resign in six centuries, and his departure -- after nearly eight years at the head of the world's 1.2 billion Catholics -- ushers in a period of great uncertainty for the church as the cardinals work to elect the next pontiff. Whoever steps into Benedict's red papal shoes will be expected to deal with unresolved questions about alleged corruption, child sex abuse by priests, leaks from inside the Vatican and, most recently, Italian media reports alleging an episode involving gay priests, male prostitutes and blackmail. More than half the 115 cardinal-electors expected to take part in the conclave were appointed by Benedict, suggesting his influence will live on. Video footage released by the Vatican on Friday showed the doors to the papal apartment there being ceremonially sealed by senior officials. They will remain closed until a new pope enters. CNN's Hada Messia and Richard Allen Greene reported from Rome and Laura Smith-Spark reported and wrote in London.