Corrections in red.  Stylistics in blue.

What is Siberia?  Do you know?

I am originally [1] from a small town in Siberia. It's really small, and there is nothing interesting there, but I'm happy to have been born there.
I am proud of the [2] people of my homeland. They just do their job - they extract oil and never cry.
Actually Siberia is a very large region with beautiful, wild nature. We have forests, endless marshes, great rivers, and the world largest freshwater lake, Lake Baikal.

[1]  I have the impression from your comment to Nelson, and from your later use of the word "there" that you no longer live in the small village where you were born.  I therefore added the word "originally" to make it clear that you now live somewhere else.

[2]  You wrote "dour" which is a word which means stern; obstinate; also:  ill-humored; gloomy; so maybe you didn't mean that.  Or did you?  If you did, then you need the article "the" -- "I am proud of the dour people......"  Perhaps you meant to write "our", not "dour"?  If so, the sentence sounds more natural with a simple "the".

What is Siberia do you know what Sibera is?

I am from a small town in Siberia. It's really small and there is nothing interesting there but I'm happy to have been born there.
I proud of dour (my) people and of my homeland. They just do their job - they extract oil and never cry.
Actually Siberia is a very large region with beautiful wilderness nature. We have forests, endless marshes, great rivers, the world largest lake, Lake Baikal.