Error analysis: present and past verbs (Chapters 1 - 3)

Please correct the errors appeared in the following sentences:

1. Since I came to this country, I am learning a lot about the way of life here.
2. Before I come here, I never was buying anything from a vending machine.
3. I arrive here only a short time ago. I am here only since last Friday.
4. When I arrived here, I hadn't known much about the United States. I saw many movies about America, but that wasn't enough.
5. My understanding of this country changed a lot since I arrived.
6. When I was in my country, I had coached a children’s soccer team. When I came here, I had wanted to do the same thing. Now I am coaching a soccer team at a local elementary school. I am coaching this team for the last two months.
7. My grandfather had lived in a small village in Italy when he was child. At nineteen, he had moved to Rome, where he had met and had married my grandmother in 1947. My father had been born in Rome in 1950. I am born in Rome in 199.
8. I’m living in my cousin’s apartment since I have arrived here. I’m not able to find my own apartment yet. I look at several places for rent, but I don’t find one that I can afford.
9. How long you been living here? I been here for almost two years.
10. Why you do have been in class the last couple of days?