Hi there here are the answers
1.Our school principal visited our class today
2.All students will take the test next week
3 The math teacher surprised all of us
4.That is my favorite notebook
5. Today is a holiday
6.I saw Mr.Clarke yesterday
Side Notes : words like test,or holiday are not capitalized because they are not descriptive like Christmas or Pacer Test.
also the beginning letter of each sentence must ALWAYS be capitalized