Before doing the quizzes, you need first to understand the layout of the folders. Basically there are main folders. These are:
The grammar worksheets include quizzes on all the main topics. The quizzes are either one or two pages. You only need to write the answer in your notebook. When finished writing the answers, go to the last page and check your answers.
Once you download the pdf file with the answers, right click read aloud and you can hear the answers being read out to you. This will improve your pronunciation of the words and your overall reading skill.
You do not need to do all the quizzes. You can be selective and you may choose the quizzes that appeal to you more interesting than others. You follow the same procedures with the other two main folders. Good luck to you with the quizzes.