For the first time

"I don't where I can find this post..I just try."

I'm not sure what you mean by finding this post. If you want to see it again, you can go back to your profile and find it under your notebook entries.

"I'm learning to English.still poor,but I can help someone who is foreigner."

I'm learning to English. It is still poor, but I can help someone who is a foreigner.

You don't need to add "to" in that sentence. Usually you can omit words, but "It is" and "a" is important in this sentence.

"Most foreigner who comes my hometown speak English.."

Most foreigners who comes to my hometown speak English.

the S in foreigners is used to signify plurals (more than one). And you do not need the S in comes.

"And I started to learn Spanish,Chinese,and how to teach Japanese."

And I also started to learn Spanish, Chinese, and how to teach Japanese.

This sentence is actually really good. Just omit "And", then put "also" before started and this sentence is good to go.

"These are so difficult,but I'm curious!"

These are so difficult, but i'm curious!

This sentence is also good. Just add a space after but, and make the i in i'm lowercase.

"Now..in my house,a foster dog and a pregnant stray cat.I take care them every day.
Pregnant cat is going to have her baby soon.Hope She and her baby are safe..."

Now..In my house, I now have a foster dog and a pregnant stray cat. I take care of them every day. The pregnant cat is going to have her baby soon. I hope she and her baby are safe.

This was a hard one, but you did pretty well! You didn't need "Now" in the beginning of the first sentence, but rather the addition "I now have" before you describe the state of your house.  "of" was needed in between "care" and "them". When you describe something, make sure you start it with "The", at least in this case. and in casual speak, usually you don't need "I" in the last sentence, but for learning purposes it is better to have it in there.

Your English is coming along well. Keep studying!