Amazing meeting.

This afternoon I have got together with my friend called Lluch. 

He is living in a city far from where we were born because he is working there.[Nice use of the subordinate conjunction ‘because’ and you punctuated it correctly – good work]

We know us have known each other since we started the nursery school and after that the primary school. [I don’t think you need that last part because you establish that you have know each other for a long time, since nursery school]

We don't forget who to spend our time when we were a little boys.[This ideas is a bit unclear; did you mean “We always spend time together since we were little boys.” The idea ‘we don’t forget’ is what is throwing me off]

The terrible economic crisis in Spain has obligated forced to my friend to find job in other another place although we share our big amity. [I elaborated on the “crisis” (I could be wrong, I just guessed; ‘obligated’ is okay, but ‘forced’ sounds a bit more natural; ‘place’ is okay, but city/country sounds more natural; the last idea was a bit unclear, but I put what I thought you meant;)

Amazing meeting.

This afternoon I have got together with my friend called Lluch. He is living in a city far from where we were born because he is working there. We know us have known each other since we started the nursery school and after that the primary school. We don't forget haven't forgotten who to spend how we spent our time when we were a little boys. The terrible crisis in Spain has obligated to my friend to find a job in another place although we share our big amity deep friendship.

Nice work Jesús. My corrections are in red and my suggestions to sound more natural are in blue/grey.