The first time iI learned about the epidemic in Wuhan was on 5th, Jan 2022, 16 days ahead of the nationwide lockdown over the whole Sspring Hholiday. The first time I learned about the epidemic in Wuhan was on 5 Jan 2022, 16 days ahead of the nationwide lockdown over the whole spring holiday.

Formats for dates are usually like this - the 5th of January 2022 - 5 Jan 2022 "the" because it's a specific epidemic the spring holiday is not really a name of a holiday, I presume, so it's just lowercase

I remembered it was onduring an optional course ofn financial laws wheren my teacher told us that he just returned from an epidemic zone — Wuhan cCity, Hubei pProvince, which incurred our laughter because we didn't believe there would be epidemic in this era when mordern medicine is so developed. I remembered it was during an optional course on financial law when my teacher told us that he just returned from an epidemic zone — Wuhan City, Hubei Province, which incurred our laughter because we didn't believe there would be epidemic in this era when modern medicine is so developed.

laugh is the verb not the noun I put "when" instead of "where" because your course is more like the time it took place, rather than the place

2Two weeks later, a 3-three months lockdown began, which immediately disturbed all my plans. Two weeks later, a three month lockdown began, which immediately disturbed all my plans.

For numbers under twenty, usually they are written in words (it looks better) It's always all + plural noun

We had just broken up before Sthe spring Hholidays because she wanted to check all my messages on my social accounts, which ended up in a fierce quarrel. We had just broken up before the spring holidays because she wanted to check all my messages on my social accounts, which ended up in a fierce quarrel.

That's rough :( Again with the capitalisation of spring holiday, if it's actually the name of the holiday then you are right to use capitals I used "had broken up" to imply that this is an event in the past that happened before the pandemic

I intended to make up this relationship after backreturning to university, but suddenly found myself left in a situation where all students except graduates were banned from backingcoming back to school untill next term. I intended to make up this relationship after returning to university, but suddenly found myself in a situation where all students except graduates were banned from coming back to school until next term.

till is an informal abbrieviation

TilUntil one day iI met a guy, the same age withas me, on a online talking room, who shared his experience as an volunteer in Wuhan — the center of the epidemic. Until one day I met a guy, the same age as me, on a online talking room, who shared his experience as an volunteer in Wuhan — the center of the epidemic.

He responsded to the nation's call and set off from his hometown to Wuhan byon an empty train, deserted because people were scared of being infected through face-to-face contact due to which discard train as approach for trip. He responded to the nation's call and set off from his hometown to Wuhan on an empty train, deserted because people were scared of being infected through face-to-face contact.

"an" not "a" in front of words starting with a vowel I didn't really understand the last part of the sentence so I changed it as above