The Sposi Novelli blessing is a part of the ordinary general audience, not a private audience. The Bishops' Office for United States Visitors to the Vatican, run by the Pontifical North American College, states the conditions: the couple must have been married in the Catholic Church within two months and up to six months before the audience, must carry a copy of the sacramental marriage certificate signed by the priest or deacon, and should wear their wedding attire, with covered shoulders for the bride, or traditional wedding dress from their culture. Requests go in at least two weeks before the audience through the office's online form, and tickets are collected the Tuesday afternoon before. Couples who qualify often sit in a special section near the front. The Prefecture of the Papal Household confirms that audience tickets are always free.
Rome and Assisi is the classic week: three or four nights in Rome around a Wednesday, then two nights in Assisi for the tomb of St. Francis and the quieter evenings. Couples who want sea time pair Assisi with the Amalfi Coast, which puts Pompeii's Shrine of Our Lady of the Rosary within reach. Lourdes and Paris suits couples drawn to Marian devotion: the sanctuary at Lourdes, then Rue du Bac and Notre-Dame in Paris.
Many couples book a short priest-led segment, usually the Rome days, and travel independently for the rest. The existing page on the best pilgrimage for couples covers the choice between destinations in more depth.