The Trinity comes from Tradition.
Our belief that there exists 3 persons in One being is not specifically found in Scripture but is found in Tradition.
The Incarnation comes from Tradition. The belief that Jesus CHrist is both fully Human and fully Divine is not specifically found in Scripture, but is found fully in Tradition.
The Theotokos, Mary as Mother of God is found in Tradition although there is evidence of it in Scripture.
Mary’s Dormition comes from Tradition.
Mary’s Immaculate Conception comes from Tradition although there is also Scriptural eviednce for it.
Mass on Sunday is an Apostolic Tradition eventhough the practice is recorded in Acts.
Christmas being on December 25 comes from Tradition.
Those are just a few off the top of my head.