Assalamu a'laykum.
First of all I want to mention that I was not a practicing muslimah before.I think I was the worst girl ever. Now I have repented. Alhamdulillah.Our family is not also practicing muslim in all way.
I have read in co-education school. There I had an affair with my classmate. My parents didn't know about that. One day they arranged my marriage ceremony with someone without my permission. I was 17 years old girl. When they insisted I went back to the boy with whom I had affair. I told him that my parents will not except our relation. And I want to cut the relationship with him. But that moment we were so emotional. I couldn't come back at my home. We married without my parents permission.But his parents knew. Although our marriage contract was held on his house. I have two witness. They were from the boy's side relatives. I didn't knew them before. They were my two witness.After that we told my parents. Then they accepted.Is that marrtage valid? My father made a condition. He didn't accept me to live with my husband's family. He told that we can lead our marriage life after finishing our graduation. Because the boy was not established,although he was a student. We have some sorts of physical relation,though we knew that we were married. But we didn't have any intercourse. Our understanding was not good. Due to lots of difficulties we both want to take divorce now. But now our parents are not excepting it for social problems. Now in this situation I want to know how we can divorce each other according to islamic law? Where I have to stay during Iddah period? Though I am living with my parents after the marriage. I am trying to apply islamic shariah in my life now.
May Allah bless you for your kind effort.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

First of all, we congratulate you upon your repentance to Allaah and we ask Him to accept it from you and to make us and you firm on His Religion until death.

You should know that there are some conditions for the marriage contract to be valid, the most important of which is the consent of the guardian. If the situation is as you mentioned in the question that your marriage contract with that man took place without the consent of your guardian, then it is a void marriage, and the approval of your father about it afterwards does not render it a valid marriage. For more benefit on the conditions of the marriage contract, please refer to Fatwa 83629.

Therefore, this marriage must be invalidated by that man divorcing you. Divorce does not need some rites for it to take effect, so if that man utters the word divorce, like if he says to you ‘You are divorced’, then divorce takes place with this statement. If your husband does not divorce you, then the matter should be taken to a Muslim judge or whoever acts on his behalf, like Islamic centers, so that they would invalidate the marriage contract.

Then, if you wish to continue your marital life, you have to renew the contract with the permission of your guardian and the presence of two witnesses. But if there is no harmony between you and your husband, then each one of you should go his own way and look for another person to marry.

Finally, the following matters should be mentioned:

1-     If the marriage contract that fulfills its conditions and pillars is concluded between a man and a woman, she becomes his wife, and anything that is permitted between a husband and his wife becomes permissible for them. Nevertheless, if according to the customs, there is a need to delay the consummation of the marriage, then this should be taken into account. For more benefit, please refer to Fatwa 91942.

2-     Being in seclusion with one’s wife behind closed doors (before consummating marriage with her) serves as having consummated the marriage with her according to the view of the majority of the scholars .

Allaah Knows best.