During weekend

Last Friday night I went out with some friends to watch a film.
The film was "Exodus", a story about Mose's life taken from the Bible. It was a very interesting film.
After that, we went to a bar to drink something and to chat.
On Saturday I met my relatives at my sister's home to celebrate my niece's birthday.
We all had lunch together and my niece was very happy about all the presents she received.
At around 4 p.m. I left my relatives to meet some other friends on the outskirts of Milano.
We went to see "American sniper". I love Clint Eastwood as a director. The film is quite strong but very realistic.
After that we went to eat pizza and to drink a beer at a Pizzeria.  -  FORMAL

After that we went for a pizza and beer at a Pizzeria - INFORMAL (some prepositions aren't as necessary)
I came back home after midnight.

Pierluigi that was a fine effort. Very well structured and your grammar is strong. Just double check the plurals and prepositions relating to the subject at hand. e.g. we get on the bus but we get in the car. I gave an informal suggestion at the end as the context of this note entry is rather casual and so not needed to be so formal.

I just saw American Sniper last night. I couldn't agree more! Well put.