If you want to know what the Catholic Church believes, and not what some Catholics may or may not believe in any time in history, it is always best to look into the official documents of thee Church on a certain subject, I think. That is not to say that there will always be one document with one level of authority that will give you one clear answer, but it still is the best way to start.
In this case you can find the answers you want rather easily, because the Church has been explicitly clear on the matter.
To quote from Nostra Aetate, a declaration of the second Vatican Council, from 1965:
True, the Jewish authorities and those who followed their lead pressed for the death of Christ; still, what happened in His passion cannot be charged against all the Jews, without distinction, then alive, nor against the Jews of today. Although the Church is the new people of God, the Jews should not be presented as rejected or accursed by God, as if this followed from the Holy Scriptures. All should see to it, then, that in catechetical work or in the preaching of the word of God they do not teach anything that does not conform to the truth of the Gospel and the spirit of Christ.
In the Catechism of the Catholic Church, a comprehensive document on what the Catholic Church believes, it states:
597 The historical complexity of Jesus' trial is apparent in the Gospel accounts. the personal sin of the participants (Judas, the Sanhedrin, Pilate) is known to God alone. Hence we cannot lay responsibility for the trial on the Jews in Jerusalem as a whole, despite the outcry of a manipulated crowd and the global reproaches contained in the apostles' calls to conversion after Pentecost. Jesus himself, in forgiving them on the cross, and Peter in following suit, both accept "the ignorance" of the Jews of Jerusalem and even of their leaders. Still less can we extend responsibility to other Jews of different times and places, based merely on the crowd's cry: "His blood be on us and on our children!", a formula for ratifying a judicial sentence. As the Church declared at the Second Vatican Council: . . .
Neither all Jews indiscriminately at that time, nor Jews today, can be charged with the crimes committed during his Passion. . . the Jews should not be spoken of as rejected or accursed as if this followed from holy Scripture.