The Lord’s Prayer is not just a rote prayer, it is a guideline for HOW to pray as well. Jesus is teaching method as well as offering a prayer to use. This is from the Gospel according to Matthew, (chapter 6):
5 And when ye pray, you shall not be as the hypocrites, that love to stand and pray in the synagogues and corners of the streets, that they may be seen by men: Amen I say to you, they have received their reward.
6 But thou when thou shalt pray, enter into thy chamber, and having shut the door, pray to thy Father in secret: and thy Father who seeth in secret will repay thee. 7 And when you are praying, speak not much, as the heathens. For they think that in their much speaking they may be heard. 8 Be not you therefore like to them, for your Father knoweth what is needful for you, before you ask him. 9 Thus therefore shall you pray: Our Father who art in heaven, hallowed be thy name. 10 Thy kingdom come. Thy will be done on earth as it is in heaven.
11 Give us this day our supersubstantial bread. 12 And forgive us our debts, as we also forgive our debtors. 13 And lead us not into temptation. But deliver us from evil. Amen. 14 For if you will forgive men their offences, your heavenly Father will forgive you also your offences. 15 But if you will not forgive men, neither will your Father forgive you your offences.
There is no prohibition against praying to, or with, the saints. There is no reason for one since honor and respect, and asking for help, are not the same as worship; worship being reserved for only GOD. But since God so honored the Virgin, then it would be unwise for us to refuse to honor her. When we pray to Mary, saying, “Hail, full of grace!” we use the greeting of the messenger of GOD.
