Давайте разберем каждое предложение, найдем ошибки и исправим их. Я выделю ошибки и напишу правильные слова.

1. My older brother can to ride a motorbike, but I can't.

   Ошибка: "can to ride". Правильный вариант: "can ride".

   Исправленное предложение: My older brother can ride a motorbike, but I can't.

2. He'll has his dinner early today because he's going out.

   Ошибка: "has". Правильный вариант: "have".

   Исправленное предложение: He'll have his dinner early today because he's going out.

3. Do you can come to my party?

   Ошибка: "do you can". Правильный вариант: "can you".

   Исправленное предложение: Can you come to my party?

4. You should to see a doctor about your foot.

   Ошибка: "should to see". Правильный вариант: "should see".

   Исправленное предложение: You should see a doctor about your foot.

5. I couldn't bought any bread because the baker's was closed.

   Ошибка: "couldn't bought". Правильный вариант: "couldn't buy".

   Исправленное предложение: I couldn't buy any bread because the baker's was closed.

6. You needn't to do the washing-up. I've already done it.

   Ошибка: "needn't to do". Правильный вариант: "needn't do".

   Исправленное предложение: You needn't do the washing-up. I've already done it.

7. The school ought listen to pupils' opinions.

   Ошибка: "ought listen". Правильный вариант: "ought to listen".

   Исправленное предложение: The school ought to listen to pupils' opinions.

8. People shouldn't to drop their rubbish in the street.

   Ошибка: "shouldn't to drop". Правильный вариант: "shouldn't drop".

   Исправленное предложение: People shouldn't drop their rubbish in the street.

Теперь у нас есть исправленные предложения без ошибок. Если у вас есть вопросы по этим исправлениям, не стесняйтесь спрашивать!