My Suggestion

Hello,

I am Nina, a 22 years old student, from Tyumen city in south of Siberia. I am currently pursuing a masters degree in international business, and the knowledge of (or understanding) multiple languages is an asset in this field. This is why I joined this site. Hopefully, it will help me improve my spoken/written English, and other languages that I am learning.

I really enjoy teaching and helping people with languages. So if you need help with the Russian language, feel free to ask me.

Your version

First notebook entry: Introducing myself

Good morning/day/evening/year/life..)  (too wordy. A simple "Hello" or "Hi" is straight forward and informal.)

My name is Nina (too short for an introduction. combine with the next sentence). I'm a 22 years old student and I come from Tyumen, small city on (in) the south of Siberia.
Now I'm doing masters degree in International Business (see revised version above). So (a bit improper) I hope this site would be useful for improving my English (insert a comma) and learning all these languages I want to speak)(period/full stop)

And also I really enjoy teaching and helping people with languages, so (proper usage. good!) if you need help in learning Russian - feel free to ask me) 

"we weren't born for one corner; the whole world is our native land" Very true, is this original(yours)? don't try to tell that to the border patrols unless you'd confuse them :).

An astronaut once said "looking at the earth from space, there are no (border)lines". I think this is also profound. :)

First notebook entry: Introducing myself

Good morning/day/evening/year/life..)

My name is Nina. I'm a 22 year old student from Tyumen, a small city in the south of Siberia.
I'm now doing a masters degree in International Business. So I hope this site will be useful for improving my English, and learning all the languages I want to speak)

And also I really enjoy teaching and helping people with languages, so if you need help with learning Russian - feel free to ask me)

...we weren't born for one corner; the whole world is our native land)

First notebook entry: Introducing myself

Good morning/day/evening/year/life..)

My name is Nina. I'm a 22 years old student and I come from Tyumen, a small city on the south of Siberia.
Now I'm doing obtaining a masters degree in International Business. So I hope this site would be useful for in improving my English and learning all these languages I want to speak)

And also I really enjoy teaching and helping people with languages, so if you need help in learning Russian - feel free to ask me)

...we weren't born forom one corner; the whole world is our native land)

Comments: You 'obtain/get/working towards' a masters degree, not 'do' a masters degree.

You are already starting the sentence with 'And' therefore 'Also' is not necessary.

Hope this helps!

))