if woman parents are christian and do not approve me as muslim and getting us married(She is also Christian), and also disagree (parents) about my nationality . What should i do?

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.

First, know that marrying this woman requires two conditions:

The first: She must be truly Christian. If she is an atheist, for example, it is not permissible to marry her, even if she claims to belong to Christianity.

The second: She must be chaste, meaning: not an adulteress.

If these two conditions are met in this woman, and you can convince her father to agree to your marriage, then that's acceptable. Otherwise, leave her and search for someone else. It's better to look for a righteous Muslim woman. If you are blessed with children from her, she will help you raise them upon the teachings and ethics of Islam. This is something you might miss in marrying a Christian woman, as she may raise her children according to her beliefs and values, which is most probably. This is why some scholars dislike marrying women of the People of the Book.

Allah knows best.