Change from Active to Passive
They sent John to boarding school at the age of ten. Before he left they gave him some spending money and his father told him to obey his teachers. They had never sent him away on his own before, so he felt a bit nervous on the train, although he knew that somebody would pick him up at the station. When he arrived at the school they showed him to his room and he
realised that he would have to share it with twenty other boys! But after some older boys had taken him round the school and invited him to play football, he knew he would be happy there.

John was sent to boarding school at the age of ten.

Before he left, he was given some spending money (или some spending money was given to him) and he was told by his father to obey his teachers.

He had never been sent away on his own before, so he felt a bit nervous on the train, although he knew that he would be picked up by somebody at the station.

When he arrived at the school he was shown to his room (или his room was shown to him) and he realised that it would have to be shared with twenty other boys!

But after he had been taken round the school by some older boys and he had been invited to play football, he knew he would be happy there.