Unimaginable store.

My friend owned a clothing store. She told me "the business was not bad, in the beginning. But after that, the business got worse and worse. I'm afraid I can't run the store much longer almost, now."

It's usually awkward to use "almost" in a negative sentence. Also, "almost" usually can't be placed at the end of the sentence.

She asked me what she could do to promote her store. I told her "Maybe, you should check your store to find what you can improve, first."

She was helpless and a little angry, she answered me, resolutely " The store is no problem, I did all of everything I could and worked hard, but customers just is are just fewer and fewer".

I'm not sure what you mean by "helpless".

One day, I just passed by the store, then I decided came in to see. I saw these shocking scenes unexpectly.

"Unexpectedly" has a neutral sound. I suggested "shocking" since it conveys a strong emotional response.

It was such a disgusting store is. She should thankful for these people who still want to come in, I thought. And she thinks this store is OK, nothing to improve.

She really fancies herself, doesn't she?! Please close the store quickly. No one can rescue you, I thought.

Nice post. The main thing you should be careful about is the proper placement of words like "just" and "almost" inside the sentence. Your meaning is generally clear though.

Unimaginable store.

My friend owns a clothing store. She told me, "the business was not bad, in the beginning. But after that, the business was worse and worse, I am afraid I can't run the store almost, now."

She asked me what she could do to promote. I told her, "Maybe, you should check your store to find what you can improve, first."

She was helpless and a little angry, she answered me, resolutely " The store is no problem, I did everything and worked hard, but customers became fewer and fewer".

One day, I just passed by the store, then I decided to come in to see. I saw these scenes unexpectly.

Such a disgusting store. She should be thankful people still want to come in, I thought. And she thinks the store is OK, nothing to improve. 

She really fancies herself, doesn't she?! Please close the store quickly, no one can rescue you, I thought.