It's de fide, a truth of the Catholic faith, that God created the universe a finite time in the past and that the universe will end a finite time into the future. Thinking the universe is eternal is a heresy.
The Fourth Lateran Council pronounced (Denzinger 428-9):
Firmly we believe and we confess simply that the true God […] by His own omnipotent power at once from the beginning of time created each creature from nothing
and that He will
come at the end of time, to judge the living and the dead
Scriptural proofs (Fundamentals of Catholic Dogma bk. 2, ch. 1, §6, 1.):
John 17:5: “And now glorify thou me, O Father, with thyself, with the glory which I had before the world was with thee.” Eph. 1:4: “He chose us in Him (Christ) even before the foundation of the world.” Ps. 101:26: “In the beginning, O Lord, thou foundest the earth.” Cf. Gn. 1:1; Pro. 8:22 et seq.; Ps. 89:2; John 17:24.
St. Thomas Aquinas defended this Catholic truth, against those (e.g., the Greeks, Aristotle) who believed the universe to be eternal, in his short work De aeternitate mundi (On the Eternity of the World). He argues this truth can only be known by divine revelation.