I mean,he's a teacher right?Does this inf. appear in the game?

I think I remember the protagoniost referring to himself as a teacher. About 2/3rd in the game. While wallowing in self pity or something.

Okay thanks.but i've got the last question,does the moment where he's being chased which is shown in trailer like render video exist in the main game?

They are a few 'timed' events with fatality risk. Nothing punishing however. They may (and some are designed to) surprise you.
The atmosphere is tense.
In the launch trailer there's no chase (I checked) or in the various gameplay trailers I know, or even in the two GOG has on the store page - so I can't tell

Hey there :) Can you point out which trailer you are referring to?
There are some tense moments, but the game is still point and click.