Bad news

Sunday was the last day of my holidays. (in America, we normally say "vacation".)

I went to the beach for two weeks. It was a sad day not only because it was my last day but also and because when I arrived home, I found at the newspaper reported that the school where I spend sixteen years of my life was burnt to ashes.  (I think you meant "I found out in the newspaper")

This school was closed in 1997 because it was in debit. They owed money to many people. Since then the school was abandoned.

It was a Bbritish boarding school, with three big buildings, and now the main buildings has disappeared. Probably, now is cheapper to buy the land, and maybe this is the reason why I it was burnt. Anyway, the school is gone but we, the students, will keep the memories. 

http://www.elcorreo.com/alava/araba/201406/29/declarado-incendio-internado-abandonado-20140629110007.html

Good job, Ana!! If you have any questions, I'm glad to try to answer them. 

Bad news

Sunday was the last day of my vacation (US) holidays. I went to the beach for two weeks. It was a sad day because it was my last day and because when I arrived home, I read in the found at the newspaper that the school where I had spent spend sixteen years of my life was burned to ashes (had burned down). The This school was closed in 1997 because it was in debt. They owed money to many people. Since then the school had been was abandoned.
It was a British boarding school, with three big buildings, and now the main buildings have dissapeared has disappear. Probably, now it is cheapper to buy the land (without the building), and maybe that this is the reason why it was set on fire I burnt. Anyway, the school is gone but we, the students, will keep our the memories.

http://www.elcorreo.com/alava/araba/201406/29/declarado-incendio-internado-abandonado-20140629110007.html

Buen obra- lo siento.

A building that catches on fire is tricky to talk about in English- so many different verbs! E.g.,

A person sets fire to a building. (there is someone or somethis that did it- you have a subject, the building is the direct object)

A building catches fire. (we may or may not know why the fire started- similar to reflexive construction)

The building burned down. (same as 'The building burned to ashes', but more natural)

Bad news

Sunday was the last day of my holidays. I went to the beach for two weeks. It was a sad day because it was my last day and because when I arrived home, I found at in the newspaper that the school where I spend spent sixteen years of my life was burned to ashes. This School was closed in 1997 because it was in debt. They owed money to many people. Since then the school was has been abandoned.
It was a bBritish boarding school, with three big buildings, and now the main buildings has have disappeared. Probably, now it is cheapper to buy the land, and maybe this is the reason why I it burnt. burned. Anyway, the school is gone but we, the students, will keep the memories. 

http://www.elcorreo.com/alava/araba/201406/29/declarado-incendio-internado-abandonado-20140629110007.html