Regarding repetitions:
[Jesus] went again: and he prayed the third time, saying the selfsame word. (Matthew 26:44)
Regarding repeating prayer:
[The judge said:] I will avenge her, lest continually coming she weary me. And the Lord said: Hear what the unjust judge saith. And will not God revenge his elect who cry to him day and night (Luke 18:5-7)
Pray without ceasing. (1 Thessalonians 5:17)
It is a good idea also to read the Holy Scripture every once in a while, and if you don't understand what you read, ask someone who is Catholic.
Those verses don’t advocate mindlessly repeating canned prayers like mantras.
What I need and want constantly changes so when I talk to God, I constantly say different things, depending on what I need.
If I don’t understand what I read, I ask the HOLY SPIRIT, not some man.