Here are the mistakes in each sentence:

1. **Sentence 1:** "should go" instead of "should do"
- Correction: "She didn't know where she should go to find the library."

2. **Sentence 2:** "the more worse" should be "the worse"
- Correction: "The longer we waited, the worse the situation became."

3. **Sentence 3:** "the easier" instead of "the more easier"
- Correction: "The more you study, the smarter you get, and the easier the exam becomes."

4. **Sentence 4:** "where he can find" instead of "where can he find"
- Correction: "He has no idea where he can find a good restaurant."

5. **Sentence 5:** "the more time you’ll have" instead of "the most time you’ll have"
- Correction: "The faster you finish the project, the more time you’ll have."

6. **Sentence 6:** "to solve this problem" instead of "for solving this problem"
- Correction: "I’m not sure what I can do to solve this problem."

### For II. Arrange the words in the correct order:
1. **"harder / the / you / the / study / get / better / results / will."**
- Correct order: "The harder you study, the better results you will get."

2. **"if / it / rains / I / know // do / cook / want."**
- Correct order: "I know what to do if it rains."

3. **"it / I / may / have / to / cancel / the / event."**
- Correct order: "I may have to cancel the event."

4. **"exercise / feel / the / you / the / healthier."**
- Correct order: "The more you exercise, the healthier you feel."

5. **"expensive / which / becomes / the / more / you / the / buy."**
- Correct order: "The more you buy, the more expensive it becomes."

6. **"the / closer / you / watch / you / if / the / bus."**
- Correct order: "You will know the closer the bus is if you watch."

7. **"you / will / call / if / he / answer / your."**
- Correct order: "He will answer your call if you call."

8. **"the / if / he / can / trip / answer / / worse."**
- Correct order: "It can get worse if he trips."

9. **"you / work / the / more / the / success / comes / closer."**
- Correct order: "The more you work, the closer success comes."

10. **"you / skills / improve / / will."**
- Correct order: "You will improve your skills."

11. **"you / rain / stay / if / indoors / starts / / to."**
- Correct order: "You should stay indoors if it starts to rain."