The hHouse wFrom When I wWas yYoung

This could be written several ways. The corrections by others also give nice ideas.

When I was lessyounger than 10 years old, I lived in a Korea traditional Korean style house.

ItThis type of house is called a 'Hanok,' and there are a few Hanok houses in Seoul, Jeongju and Andong.

My old house had three small buildings around a centeral garden.

The other building had my parents' room, where my brother and I slept.

The last building was used foras a warehouses.

Since it's a singular building, you'll want to use the singular word, "warehouse."

In the centeral garden, there were two graph trees which my father really liked.

I'm not sure what type of trees you mean here, could it be grafted trees? This would be the type where the tree is cut carefully and a new branch is added.

I had many memories in the house, especially of experiences with my grandfather.

The house when I was youngMy childhood home

It seems like your talking about your childhood house. So I changed the title

When I was less than 10 ¶
years old or younger, I lived in a Korea traditional Korean style house.

10 years old or younger is a more natural way to say. Less than 10 years old.

My old house had three small buildings asurround a center gardened by a garden in the center.

I switched some words to make it flow in English.

The main building had a clothing store, a kitchen and my grandparent’s' room.

Grandparents should have the ‘s to show possession. It means that is your grandparents room.

조부모는 소유권을 보여야 한다. 그것은 당신의 조부모님 방이라는 뜻입니다.

The other building had my parent’s' room where my brother and I slept.

조부모는 소유권을 보여야 한다. 그것은 당신의 조부모님 방이라는 뜻입니다.

The last building used foras a warehouses.

I not sure if you were trying to say one warehouse or multiple. The plural word for warehouse is warehouses.

I hadve many memories in theat house, especially my experiences with my grandfather.

I made it sound native.

Because of those memories, I still love the house very much.

I added “those” to make it sound native.

나는 그것이 네이티브하게 들리도록 "those”추가했다

The house I lived in when I was young

When I was lessyounger than 10 years old, I lived in a Korea traditional Korean style house.

It isThey are called 'Hanok' and there are a few Hanok houses in Seoul, Jeongju and Andong.

TWe used the last building used foras a warehouses.

In the center garden, there were two graph trees which my father really liked.

우리는 'father' 말고 'dad'을 보통 말해요.

I hadve many memories in theat house, especially experiences with my grandfather.

그리고 'grandfather' 아니고 'grandad' 가끔 말해요.

Because of the memories, I still love theat house very much.