There's a Chinese proverb saying: which states," Read ten thousand books, travel ten thousand miles."

I have liked the ancient poet Su Dongpo very much since I was a kid at schoolSince I was a kid at school, I've liked Su Dongpo, who's an ancient poet.

structural change

The ones chosen by our textbooks aOur textbooks had some of his poetry and the ones chosen were really outstanding.

During my travels in Hainan province, where he had been exiled by the emperor, I discovered he was a resilient and optimistic person.

Two weeks ago, when I came across heavy rain while hiking, I suddenly remembered a poem by Su Dongpo and caughthad the same feeling thats in the poem.

Back to the proverb, only after reading and travelling, can I fully be aware of the spirit in some words written by a person who lived a thousand years ago.; through their words.

Of course, it'sI am not asking you to read and travel exactly ten thousand times, but to do them as much as you cansuggesting read ten thousand books or go on ten thousand trips. However, reading and travelling extensively is good.

BRITISH SPELLING: travelling. / AMERICAN SPELLING: traveling

ALSO POSSIBLE: For nearly a thousand years, he has been widely loved by themany Chinese people.

There's a Chinese proverb saying: " Read ten thousand books, travel ten thousand miles."

Since the quote is in quotation marks, you don't need the colon here

I have liked the ancient poet Su Dongpo very mucha lot since I was a kid at school.

"very much" is grammatically fine, but it's a bit unnatural to use here.

Two weeks ago, when I came across heavy rain while hiking, I suddenly remembered a poem by Su Dongpo and caughfelt the same feeling described in the poem.

There's a Chinese proverb sayingthat says: " Read ten thousand books, travel ten thousand miles."

Two weeks ago, when I came across heavy rain while hiking, I suddenly remembered a poem written by Su Dongpo and caught the same feeling in the poem.

Back to the proverb, oOnly after reading and travelling, can I fully be aware of the inspiritation in some words written by a person who lived a thousand years ago.

There's a Chinese proverb sayingthat says: " Read ten thousand books, travel ten thousand miles."

“That says” is optional.
You can also use “,” instead of “:”.

Of course, it's not asksaying you toshould read and travel exactly ten thousand times, but to do them as much as you can.

The proverb is not a question, so “saying” or “telling” is more appropriate.

For nearly a thousand years, he has been widely loved by the Chinese people.

The ones chosen by our textbooks are really outstanding.

This is grammatically correct but is not natural. We don’t say objects, such as textbooks, choose people. People, a group of people, or concepts like the heavens, gods, or history can choose people.

Alternatives:
“The ones chosen to be in our textbooks are really outstanding.”
“The ones written about in our textbooks are really outstanding.”

Back to the proverb, o. Only after reading and travelling, can I fully be aware ofunderstand the spirit in some words written by a person who lived a thousand years ago.

There's a Chinese proverb saying: " Read ten thousand books, travel ten thousand miles."

Of course, it's not asking you to read and travel exactly ten thousand times, but to do them as much as you can.

In English we also have this proverb, but it means that reading a book figuratively transports the reader, as though they visited as many lands as the number of books they read. So you could reword your sentence to say: Of course, it’s not suggesting you need to read 10,000 books, but the more you read, the more you “experience” of the world.

During my travels in Hainan province, where he had been exiled by the emperor, I discovered he was a resilient and optimistic person.

Good job using an appositive!

Two weeks ago, when I came acrosswas caught in some heavy rain while hiking, I suddenly remembered a poem by Su Dongpo and caughtexperienced the same feeling as in the poem.

The proverb suggests that because you read about something similar, it’s like you already experienced it - so when you experienced it in real life it was like the second time.

BRelating back to the proverb, only after reading and travelling, can I be fully be aware of the spirit in somof the words written by a person who lived a thousand years ago.