Hello, My name is inyoung bae,
-> Hello, my name is Inyoung Bae,

I'm in my mid 40s.
-> Correct sentence!

I Graduated from dong-a university which is located in Busan city.
-> I graduated from Dong-a university which is located in Busan city.
 
Busan is habor city where is famous for ??? beach,??? and ???.
-> Busan is a harbor city which is famous for  beaches.

I majored in computer science and work for SamsungSDS as a senior manager.
-> I majored in Computer Science and work for SamsungSDS as a senior manager.

I'm married and living with my wife and two sons
-> I'm married and I live with my wife and two sons

and there are four people in my family.
-> Correct sentence!

My wife is in her early 40s and she is typical housewife.
-> My wife is in her early 40s and she is a typical housewife.
 
She is responsible for housework in general
-> Correct sentence!

and also take care of two sons
-> and she also takes care of our two sons

who are middle school student.
-> who are middle school students.

They are only one year apart and have the same birthday.
-> They only have a one year age gap  and have the same birthday.
 
Younger brother is taller than elder.
-> My youngest son is taller than his elder brother.

I live around the Suwon area where is near to my workplace.
-> I live around Suwon which is near my workplace.
 
In my spare time, I enjoy eating out with my family
-> Correct sentence!

and sometimes playing socccer,badminton, table tennis with my sons.
-> and sometimes I play socccer, badminton and table tennis with my sons.

I'm happy to have such a nice family.
-> Correct sentence!

I am a positive person and my motto is that simple is the best.
-> I am a positive person and my motto is that "Simplicity is the best".

Thanks for listening.
-> Correct sentence!

Hi!

I'm glad to know a lot of personal information about you! You did a wonderful job introducing yourself through this writing.