To be better at school, you should sleep earlier.
You should do your homework right after school and everyday.
You should pay attention in class and be quiet.
You shouldn't chat in class and you shouldn't skip class too.
Also, you shouldn't be absent-minded. You shouldn't forget your books and textbooks.
Finally, you should enjoy all your classes !
J'espère que c'est assez et j'espère t'avoir aidé !