New MyMy new workplace

It’s athe first time to go to a new place for me.

That’s because I was not sure that I can fit in in the new workplace andwith its members who I haven’t ever met.

"in in" might look a little strange here at first glance, but "fit in" acts like a single verb and then the second "in" is part of "in the workplace" to locate the action.

You can't "fit in members" but you can "fit in with" members, so I changed the "and" to a "with"

Now, I am enjoying the new work and workplace with polite colleagues!

My primary work is public releases of our government policies and informations.

"information" is uncountable, and so basically works as its own plural.

This task aim to not only domesticis not just aimed at Japanese people but also foreign residents fromin Japan.

"domestic" in English is a little ambiguous if it just counts citizens or also permanent residents etc., so it's better to just say Japanese here I think.

Therefore, I should do the releases byin Japanese and English.

It’s hard to me ifas I’m not good at using English.

So, I wish I want to be a good at English user as soon as possible.

"I wish" and "I want" convey the same meaning here, so it's better to pick one

We don't really say "a language user", but rather "a language speaker". This can be a little confusing when you're talking about specifically writing rather than speaking, so I rephrased the sentence to avoid it.

It’s amy first time to go to new workplace for me.

What you wrote is grammatically correct, but a little unnatural.

That’s because I was not sure that I can fitwould fit with the new workplace and its members who I haven’t ever met.

But that’s aI didn't needless to worry.

What you wrote is grammatically correct but I don't think I would say it like that. I changed it to a more native-sounding expression.

Now, I enjoy my new work and place with polite colleagues!

My primary work is the public releases of our government policies and informations.

I always think of "information" is uncountable kind of like "bread". If you want to make it countable you could say "pieces of information", but that's pretty rare.

This task aim to not only domestic peoplis aimed at not only native-born Japanese but also foreign residents fromin Japan.

I'm not sure what the standard phrase is in Japan anymore, but I heard phrases like "native-born Japanese and foreign residents" when I lived there, I think.

More simply you could say "They are for everyone who lives in Japan, no matter where they are from."

Therefore, I should do the releases bypublish them in Japanese and English.

So, I wish I want to be a goodget better at English user as soon as possible.

What you wrote was correct but a little unnatural. I changed it to something a bit more native-sounding.