But for the past three months, I've got so many things to do.

or, even better:

But for the past three months, I've had so many things to do.

Apart from my 9-to-5 job, I was occupied with preparing to takefor the IELTS exam.

Your original sentence is grammatically correct but this is more how'd we write it in the US.

One benefit that I can think of is that people wouldill try to figure out how to manage their time and tasks more efficiently in athe hopes that they can have more time to unwind.

Another is that they can gradually build up resilience to a heavy and time-consuming workload, so, if they face it again in the future, they wouldn’t struggle as much.

However, rRemaining occupied with work or study, however, can result in stress, anxiety, depression, or even illness.

Since games are engaging, children tend to actively participate in the process and pay high attention, which means that they are likely to learn what their teachers are trying to educateteach them.

4 What kind of pressure domay people may experience at work?

or

4 What kind of pressure do people experience at work?

One is having to deliver work toby an urgent deadline.

The fear of the possibility of missing thea deadline can make people restless and constantly on edge and restless, and can cause them to overwork.

Unexpected changes such as increasing workloads or work hours without notice or a staff shortage can really stress people out, too.

But for the past three months, I gothad so many things to do.

"I got a lot to do" sounds like they are still things that have to be completed / they're still unfinished; but if you've been busy for the past 3 months, i think you'd have finished a lot of things. (with more to come i guess, but you're just talking about the months in the past here)

Unfortunately, he assigned a lot of homework, so after a busy day at work, I still havehad little time to rest as it took me forever to complete all the assignments.

have = present, had = past
also "still" doesn't really make sense here

2 What are the advantages and disadvantages when people keepof being busy?

i'm assuming this is a question you got from some other source - maybe homework from your wonderful IELTS prof? lol
but i did a bit of a double-take when reading it because it initially looked incorrect, but it wasn't. it was just a very odd phrasing. i think if it's unusual enough for me to to double-check then it's worth rewriting more naturally, even if it wasn't something you wrote

One benefit that I can think of is people would try to figure out how to manage their time and tasks more efficiently in athe hope that they can have more time to unwind.

you could also write "in hopes of having more time to unwind" ; i just wanted to keep the correction closer to what you had originally written.

Another is they can gradually build up resilience to a heavy and time-consuming workload, so if they face it in the future, they wouldn’n't struggle.

this sentence does sound natural, but if you're preparing for an english exam i thought i'd include this

if [present tense] , then [present tense] OR [will/can/must + verb] OR [imperative]
if [past simple] , then [would/could + verb] -- ex. if it rained, then you could get wet.
if [past perfect] , then [would/could (optional: have) + participle/verb] -- ex. if it had rained, then you could have gotten wet.

you wrote "if they face" which is the present tense, so the verb in the following clause has to be one of the options i gave. (i chose will + struggle) for you to say "they wouldn't struggle," the if-statement would have to be like "so if they had faced it in the future" which makes no sense since you'd be using the past perfect to refer to the future lol

However, remaining occupied with work or study can result in stress, anxiety, depression, or even physical illness.

depression & anxiety are (mental) illnesses themselves, so i think you meant it could cause more physical symptoms like nausea or something.

For me, it would be better if children learned through playing games.

or "learnt"
same as the if-then thing i wrote before:

then [would + verb] -> if [past simple OR past perfect]

On the other handFurthermore, games with educational toys have long been proven to be an effective way of learning for children.

"on the other hand" usually introduces something that contradicts your previous statement/reasoning. your previous statements were against pressure / for games - and this sentence also is for games & against pressure. so you should use a word/phrase that links similar statements, like furthermore, in addition to, moreover, additionally...

Since games are engaging, children tend to actively participate in the process and pay highclose attention, which means that they are likely to learn what their teachers are trying to educateteach.

or: pay a lot of attention, although "close" sounds much better

you can educate people, not things. to educate someone is to help them learn; a thing (especially a school subject, like reading) cannot learn anything as it has no brain... but you can *teach* people as well as things. so you can say here that a teacher is educating or teaching children, but they are only teaching mathematics. one cannot educate mathematics.

4 What kind of pressure do people may experience at work?

or: What kind of pressure may people experience at work?

this one was actually incorrect 🤔

I can imagine many occassituations that can make people feel pressured at work.

occasion refers to moments in time or opportunities. it's usually the environment or situation somebody is in that causes anxiety, not a particular time or opportunity.

you could write: I can imagine many occasions where people feel pressured at work.
they feel pressured *during* those occasions, not because of them.

One is having to deliverfinish work toin an urgent deadline.

or: One is having to deal with urgent deadlines.

The fear of the possibility of missing the deadline can make people constantly on edge and restless, and can cause them to overwork.

this sentence feels really long to have no comma, i would have probably put one there as well, but if you want to take an exam i imagine test-graders will get pissy about Correct English Grammar

"and" is a coordinating conjunction. it joins 2 clauses. your 2 clauses here are (shortened for my sanity): "The fear can make people on edge and restless" & "can cause them to overwork."
your first clause (the one that i shortened) is an independent clause. you could write it alone, as it is, and it still makes sense as a complete sentence. it has a subject, a verb, and a predicate that expresses a complete thought.
your second clause is not an independent clause. you couldn't write "can cause them to overwork" as a sentence on its own as it is. it has a verb and a thought, but no subject. it is a dependent clause. it depends on an independent clause for either a subject, verb, or complete thought. in this case, your 2nd clause depends on your independent clause for a subject: people
because your dependent clause needs your independent clause to work, it cannot be separated afterwards with a comma. it has to be written all together. (although, like i said, it's a long sentence so most people would have included a comma just as a mental pause)

HOWEVER since this is such a fun language: if your dependent clause goes BEFORE your independent clause (which usually requires a subordinating conjunction and not just a coordinating conjunction) then it must be separated with a comma. Ex: Since (sub. conj.) I was tired, I decided to go to bed. ("I was tired" is a complete sentence, but "since" implies that there will be further information - and without the independent clause afterwards, we don't know what that is, making it an incomplete thought. so "Since I was tired" is still a dependent clause.)