Какие предложения написаны неправильно, а какие правильно?

1. Tom, which was a manager, now are homeless.
2. I wish I hadn't gone to the party yesterday.
3. If I were you, I would read more.
4. While my sister played computer games, I was help my parents.
5. You mustn't do your homework today. You don't go to school tomorrow.
6. We arrived at the station after the train had left.