All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is forbidden for you to be in contact with a non-Mahram woman till you marry her.
Marriage to a woman from the People of the Book is permissible if two conditions are met: 1) She should believe according to the People of the Book; and 2) She should be chaste.
Allah Says (what means): {And [lawful in marriage are] chaste women from among the believers and chaste women from among those who were given the Scripture before you, when you have given them their due compensation, desiring chastity, not unlawful sexual intercourse or taking [secret] lovers.} [Quran 5: 5]
If the mentioned two conditions are met, then one may marry her. However, it is a fact that many of them became atheist and most of them do not know the meaning of chastity. Even if it is supposed that the conditions are met, it is better to a marry a Muslim woman to have a stable life, full of love, and concord with the safety of his children’s faith.
Finally, we warn you against having any relation with a non-Mahram woman since it leads to many bad consequences.
Allah knows best.