You are correct. The church did not, as Vespa300 claims, move the Sabbath to the first day of the week. The section of the catechism that he references is called The Lord's Day. It explains the origination of Sunday worship but clearly says "Sunday is expressly distinguished from the Sabbath."
The Catholic Church claims that “the church is above the Bible, and this transference of Sabbath observance is proof of that fact” (Catholic Record of London, Ontario Sept 1, 1923).
We observe Sunday instead of Saturday because the Catholic Church, in the Council of Laodicea, (AD 336) transferred the solemnity from Saturday to Sunday.
Convert’s Catechism of Catholic Doctrine, by Peter Geiermann, published in 1928
There are literally hundreds of quotes.