When I was in middle school, I had nine subjects: Chinese, English, mathematics, politics, history, geography, physics, chemistry, biology.

You should say, 'I took nine subjects' or 'I studied nine subjects'.

Politics always told me what was correct and what was incorrect, but I didn't think it made sense.

'In politics there was always a right and wrong and it didn't make much sense.'

I hated history because history had many historical eventevents and dates that I needed to remember, butand I didn't like to remember those things.enjoy memorising them.

My opinion was that all the things had passed and they might have nothing to do with nowadays.

I believed these things had already passed and had little relevance nowadays.

Geography also needed me to remember things, but all the things are visible, for example, coal mines, grasslands, mountains, deserts and so on.

Geography also required me to memorise things, but physical things like coal mines, grasslands, mountains, deserts and so on. (etc)

As to mathematics, physics and chemistry, it's hard to say whether I liked them or not, but I had to learn them, regardless otherwise, I wouldn't gainet good enough grades.

However, they were better than politics and history because you didn't need to remember too many useless things.

You could change 'useless' to 'pointless'.

In my opinion, science subjects mean smartare more logical while liberal subjects mean diligent.are more creative?

When I was in middle school, I had nine subjects: Chinese, English, mathematics, politics, history, geography, physics, chemistry, and biology.

What you wrote is acceptable, however writing 'and' at the end of a list before the last word is more common and natural.

Politics always told me what was correcright and what was incorrectwrong, but I didn't think it made sense.

What you wrote makes sense completely but it sounds more natural this way with good collocations :3 Your choice whether to keep it the same or not :

GIn geography, I also needed me to remember things, but all thof those things awere visible, for example, coal mines, grasslands, mountains, deserts, and so on.

Geography also needed me to remember things - it's more of a poetic/creative way of putting it. A subject does not have emotions or needs so I would change it. Also, I would stick to the past tense.
Use a comma after the last word in a list, before 'and' e.g. "I bought bread, milk, and lettuce."

Some of them were published in my local newspapers.

As tofor mathematics, physics, and chemistry, it's hard to say whether or not I liked them or not, but I had to learn them, otherwise, I wouldn't gainet good grades.

Remember comma after 2nd to the last word in a list - physics,
I made the 2nd part of the sentence sound more natural.
'Get' instead of 'gain' sounds more natural here

You only needed to remember basic formulas and you would do well oin the subjects.

In my opinion, science subjects mean smart while liberal subjects mean diligent.

I don't know what you wanted to say here

Time neither goes back, nor do I go back to the past.