The eight week summer vacation is a good time for you to work on improving your English. In fact, if you do nothing at all in the summer, you may find it difficult at the start of the new school year. It is particularly useful if you can concentrate on the aspects of your English where you are not so strong. (If you don't know what they are, ask your ESL teacher!)
All of the suggestions in the above list can be useful, but probably the best thing to do in the summer is: READ. Reading in English can increase your vocabulary, improve your spelling, help you learn grammar, and make you a better writer. Reading English books and discussing them with your parents in your own language is a good way of increasing your understanding of the elements of fiction - for example, how writers describe setting, create interesting and believable characters, develop plot, explore a theme, etc.
It may seem strange, but if you read good books - both fiction and non-fiction - in your own language, it will help you in English, too. This is because reading is like any other skill - the more you practise, the better you become. Reading also increases your knowledge of the world around you, which can help you when you come to study different topics in your school subjects. And once again, discussing what you read with your parents in your own language will help you to deepen your understanding.
All these are good reasons to read, but the most important reason is that reading can be such an enjoyable activity - particularly when you yourself choose what to read.
Another very useful way to prepare for the new school year is to find out what topics will be taught in your subject classes in the next grade; for example, in science or humanities. If you borrow a textbook, you will be able to read up about those topics in advance. Or you could read about the same topics in a textbook or encyclopedia in your own language. If you discuss what you read with your parents, in your own language, this will help you to understand the topic even better. (See the next section for advice on how to prepare for your English class.)
If you are taking mainstream English in the next grade level, you could find out which short stories are planned for the year, and read them in advance. I suggest the following method:
Some students like to do a summer language course. (Or their parents like them to do it!) It can be fun to stay in an English-speaking country and it should help you to improve some aspects of your language. But it's important to chose the right course, or you may be unhappy and not learn anything. It's a good idea to talk to your ESL teacher if you are thinking of doing a vacation language course.
Instead of doing a language course, you could sign up for an activity holiday organised for native speakers of English. For example, you could attend a basketball or tennis camp, or you could do a computer course. Another possibility would be to learn horse-riding or mountain climbing. This would be an excellent way to improve your spoken English, learn a new skill and have a good holiday, all at the same time! One British company that offers many different activity holidays is PGL. [More suggestions on summer courses]
Don't spend all your summer working on English. You have probably worked very hard all year, and you now need to have a complete rest. This will help you be ready for the next school year with renewed energy and enthusiasm.