Since this website was designed to be used to aid learning and to prepare for quiz competitions, most quizzes are set on basic topics. Most quizzes cover a topic in general.
No two quizzes contain the same question, so you can do them in any order you like. But some quizzes are more difficult than the others, so it's always better to start from the easier topics, like the solar system, planets, night sky.
We will consider your suggestions when planning future quizzes. You can make suggestions to the available quizzes by using the comment box at the end of each quiz.