Being punctual will really help you to succeed in your studies. First and foremost, punctuality ensures that you will arrive on time to classes and so will not miss any part of the lesson.
Punctuality during school life will also help to prepare you for your working life. If you get into good habits of punctuality during your school years, you will find it easier to always turn up to your work on time and thus to get ahead in your career as well.
Finally, punctuality is, quite simply, a polite skill to cultivate. Your teachers will have put a lot of effort in to preparing their classes and so it is important that you turn up on time so that you do not mess up their plans.
What about if you have an unavoidable emergency, or an appointment that cannot be moved, that means that you will need to miss a portion of the school day? In these cases, it is crucial to tell your teachers well in advance.