Людии, пожалуйста проверьте правильность предложений, очень сомневаюсь, что все написано правильно.
Welcome to our school! Here all pupils should wear a school uniform. For sports there is a gym, in warm weather you can practice on a street sports field. Near the beds, and there is a garden behind the school. All teachers have their own classrooms in which they conduct subjects. At school we get a lot of knowledge and skills.

Но лучше сказать outside. in the street - это на какой-то улице

1. school uniform (без артикля), ...classrooms, where they conduct

Тоже можно

как раз-таки school uniform надо с артиклем

выражение a lot of knowledge - нежелательно так употреблять

Welcome to our school! all the pupils should wear a school uniform here. For sports there is a gym, when the weather is warm, you can practice outside, on the sports field. Near the beds there is a garden behind the school. All the teachers have their own classrooms where they conduct subjects. At school we get knowledge and a lot of skills.

ВотWelcome to our school! Here all students should wear a school uniform. For sports there is a gym, in warm weather you can go in for sports on the street. Next to the beds there is a garden behind the school. All teachers have their own classrooms in which they conduct subjects. At school, we get a lot of knowledge and skills.