Hello, Van! Here, I corrected a bit for you:

Fatherland
All persons People all over the world have a fatherland - a place where they were born, grew up and where  many fond warm memories of their early childhood come from. My fatherland was is a poor village in Vn
In early primary school I had no bicycle and had to walk through the fields and over streams to get to school. It was easy in the summer, but much more difficult in the winter.

There were no computers or similiar technology at that time.....Fields, streams and my paper kites were my life in my early days, and I will cherish the memories forever.
After school we had to work in the rice fields. I used to send Sent my wishes on a paper kite in those times.

feather land

Fatherland
All persons Fatherland all over the world. Where ever they were born. The fond memories of early childhood.

My fatherland was a poor village in Vn
In early school. I had no bicycle walked through fields and over streams to school. It was easy in the summer but much more difficult in the winter.
There were no computers or similiar technology. (at that time)? <em>redndant, we know it is an earlier time by the verb were. </em>Fields, streams, and my paper kites were my life.  (early days is redundant.. Again, Tautology.. Redundancy.. It's infered by the usage of the past tense that we are talking about early days.) 

After school we had to work in the rice fields. I Sent my wishes on a paper kite. (In those times... Look up the term overstatement.. Tautology... Half of your passage simply repeats the other half.