Scripture did not suddenly appear 360 yrs after Jesus’ death! It had been used long before this, as it was written long before this.
Scripture came after the Mass. Scripture was always read in celebrating the Mass, and the Mass developed structure as the Church was established. Scriptures were then adopted into the first Masses as they were written and given to specific communities.
Remember, Jesus held one of the first Masses with the Disciples on the road to Emmaus! He explained the Scriptures to them, with divine interpretation, but it was His Eucharist which opened their eyes!
As my signature records from Acts, the first Masses were devotions to the Teachings of the Apostles, the breaking of bread (Eucharist/Lord’s supper) and the prayers.