2. What do you think is interesting about Japan after you came to Japannow that you're here?

I think this way might be a little bit smoother, or more colloquial (if the context for the conversation is a language meet-up in Japan).

DidHave you been able to smoothly order what you want to eat smoothly at a restaurant?

4. My friends travel to other countries because they like to visit world heritage sites and dgo museum-hopping.

What's your main purpose ofor taking overseas trips?

They're not customized in tastespecially for tourists, unlike the restaurants introduced on thein guidebooks.

I want to enjoy the real local dishes in other countries.

TheMy second purpose is watchingto see [or to look at, or to visit] fairy-tale-like buildings.

5. Have you ever had an embarrassing experience in another countriesy?

While I was waiting for the traffic signal to turn to green, I godt a lot of bird's droppings on my head and, my right shoulder, and my bag.

There were many people on the other side tof the street waiting for the traffic signal.

My mind went brlank and I froze there.

I was so embarrassed that I ran away, almost in tears for a back alley.

In Japan we canould get a half -baguette sandwich without saying anything.

Even a drink, the cup size isthe cups for drinks were much biglarger than that ofin Japan.

I tore the bread into two and, ate one half there, and put the other in my bag after wrappeding it with some pieces of paper napkin.

2. What do you think is interesting about Japan after you came to Japan?

Sounds a little weird but it's not wrong. I would say "What do you think is interesting about Japan after you went there?" Or "What do you find interesting about Japan after you came?" No big deal but I would omit the second "Japan" at the end of the sentence.

3. What's a something that you think it's inconvenient or annoying in Japan?

It sounds a little off to me when you say "What's a thing you think..." You could also say "What's something you find inconvenient". In fact, I would recommend you say that instead.

4. My friends travel to other countries because they like to visit world heritage sites and do museum-hopping.

Making "Heritage" a plural sounds weird. I would say "sites" but that's just me :)

While I was waiting for the traffic signal to turn to green, I godt a lot of bird's droppings on my head and, my right shoulder and my bag.

Unlucky hahaha.

There were many people on the other side to waiting for the traffic signal.

Made this more concise.

My mind went brlank and I froze there.

Blank, as in empty.

I was so embarrassed that I ran away, almost in tears, for a back alley.

Makes sense but I would say "I was so embarrassed I ran to a back alley in tears". It's fine though. You could say this in a lot of ways.

6. Do you have any failure storyies in other countries?

When I went in ato Subway, a sandwich chain shop, I ordered like I do in Japan, but then I got a whole baguette sandwich.

I find it more common to refer to fast food restaurants like this: "When I went into Subway" and not "a Subway". It still makes sense though.

Even athe drink, the cup size is much bigger than that of Japan.

How could I possibly eat this?

You could also say "How could I possibly eat all of this?"

I tore the bread into two and ate one half there and. I put the other half in my bag after wrapped it with some pieces of paper napkin.

This sentence is a little long-winded, but not that bad. I'll provide how I would write it: "I tore the bread in two and ate one half there. I put the other in my bag...."

Questions Part 1

2. What do you think is interesting about Japan after you came to Japan?

You are assuming/already know that they went to Japan with this sentence. If you do not wish to do so, try
What do you think is interesting about Japan?
or
If you went to Japan before, what do you think is interesting about Japan?

3. What's a thing you think it's inconvenient or annoying in Japan?

Did you order what you wanted to eat smoothly at a restaurant?

4. My friends travel to other countries because they like to visit world heritage sites and do museum-hopping.

My main purpose is eatingto eat the local dishes at food stalls on the streets.

They' are not customized in tastespecially for tourists unlike the restaurants introduced on the guidebooks.

The second purpose is watchingto visit fairy-tale-like buildings.

While I was waiting for the traffic signal to turn to green, I god a lot of bird's droppings started falling on my head and, my right shoulder and my bag.

There were many people on the other side to waiting for the traffic signal.

My mind went brlank and I just froze there.

I was so embarrassed that I ran away, almost in tears for, into a back alley.

6. Do you have any stories of failure story in other countries?

(This question is kind of similar to 5)

When I went in a Subway, a sandwich chain shop, I ordered like I do in Japan, thenusually did in Japan, and to my surprise, I got a whole baguette sandwich.

In Japan, we canwould get a half of the baguette sandwich withouif we do not saying anything.

Even a drink, the cup size of a drink is much bigger than that of Japan.

How could I possibly eat this much?

I tore the bread into two and ate one there and put, putting the other into my bag after wrappeding it with some pieces of paper napkins.

I was almost in tears.

Elaborate why, it's not very clear here
Example:
I was almost in tears because of how much food they gave me.
I was almost in tears because I couldn't finish this much food.