The idea of working in another country has always been appealinged to me.

My dreams were shaped by the many stories I've heard from people who had studied abroad, and who became fluent in another language while I was stuck in my hometown, trying to make end meets.

I have admired people like that for so long, thabut I decidedknew my turn willould come.

Even if the task seemed daunting, I wasam among the ones who have decided to not live with no regrets.

I wasam cut out for living adventures and to succeed, whatever the amount of effort ithat will be required.

Although I' am not inclined to believe never swallowed people's speech,ything that people say, I still naively believed that I could be "fluent" in 3 months.

I dont think its a question of understanding, as per the other comment - its more that people says things and one must take what people say "with a grain of salt" - that is a very nice expression that means that you adjust things a bit for your own belief and experience

Fortunately, thereno effort is ino vain effort!.

Sounds better and the phrase 'in vain" is more commonly used.

In bothEither ways, be ready to be shaken, sometimes even chastened, d. Do not be afraid to make mistakes, and to ask for corrections.

mistakes has an 's' so corrections should too. You could also say Never be afraid to make mistakes - that may flow a little better

I used to extol the virtues of living abroad.

You have used extol correctly here, but be aware that it is a fairly uncommon word that would not be recognised by a lot of native speakers

The idea of working in another country sparked has always been appealing to me.

not sure why sparked is in there
Perhaps something like:
The idea of working in another country has always sparked my imagination.

My dreams were shaped by the many stories I've heard from people who studied abroad, who became fluent in another language while I was stuck in my hometown, trying to make ends meets.

the expression is ends meet, not end meets.

I have admired these people for so long, that I decided my turn will come.

Even if the task seemed daunting, I was among the ones who have decided to not live with regrets.

Yours was not incorrect. It was however a bit awkward.

I was cut out for living adventures and to succeed, whatevno matter the amount of effort it will require.

This is a stylistic choice

Honestly, I wasn't expecteding so much!

Although I've never swallowefully understood people's speech, I still naively believed that I could be "fluent" in 3 months.

Swallows is not the word you are looking for. It refers to eating and digestion.

It was such a bitter pill to swallow.

Good use of the expression, I have just made it more explicit although this may not be needed.

Fortunately, there is no vainwasted effort!

Vain more means selfish. I don't think this is what you are looking for.

You can either set reachable goals to achieve over time or get married to a native (the faster option).

In both ways, be ready to be shaken, sometimes even chastened, do not be afraid to make mistakes, and to ask for correction.

chastened is correct, but once again an unusual word.

I would suggest something like:
In both ways, be ready to be shaken, sometimes even rebuked, do not be afraid to make mistakes, and to ask for correction.