Today I was doing some sightseeing uoutside of Berlin, and my family and I went to Postdam, it's a beautiful place with a lot of palaces.

However we only coughtcould only visit one of them.

Its called Sans Souci's Palace, it's a big house with large gardens, fountains and longer paths.

One thing that wonderamazed me, was the public transport, what an efficient waything.

you can't wonder yourself in English. You either wonder at something or something amazes you.

In berlin, you can buy a 'seven days' ticket and you will be able to take buses, tranvia, metro, urban trains, ferryies and outsideregional trains to closer cities.

'outside train' doesn't make sense in English, you'd say regional train here. It is also correct to specify these list items in plural, unless they are a 'system' like the metro. I can't explain why, but you take buses (or the bus), but you take the metro

aAll in one, so this city haves the most efficient public transport siystem.

There is an urban miyth in Latin America about the gGerman people, that they are sullen, but I noticed that it's a linot true, they are nice very polite and beautiful.

saying something is a lie implies someone tried to deceive you. You'd just say 'not true' here because probably the people that told you this weren't lying on purpose, they were just wrong/mistaken

I hope so know another places of this vibrant city next days.

I don't understand what you mean here

Today I was doing some sightseeing uoutside of Berlin, m. My family and I went to Postdam, it's a beautiful place with a lot of palaces.

Alternatively: "Today I was sightseeing outside of Berlin. ..."

However we only coughtgot to visit one of them.

Alternatively, you could say "we could only" instead of "we only got to". "Get to" and "could" have very similar meanings, but "get to" has just a little more energy and is what I would probably use in this scenario.

It's called Sans Souci's Palace, i. It's a big house with large gardens, fountains and longer paths.

In formal writing, "it's" is a contraction of "it is" – note that the apostrophe takes the place of the second "i". "Its" is the possessive form of "it", which doesn't have an apostrophe just so that it can be differentiated from "it's".

One thing that wonderfascinated me, was the public transport, w. What an efficient way of travelling.

As a verb, "wonder" means to question to oneself. Like, "I wonder what's in that box?" You probably mean a word like "fascinate" or "amaze".

It's better to specify of WHAT it is an efficient way of doing.

In bBerlin, you can buy a seven days ticket and you will be able to take the bus, tranviam, metro, urban train, ferry and outside train to closer cities.

My browser's spell-checker doesn't recognize "tranvia" as an English word. Do you mean "streetcar" or "tram"?

It's all in one, so this city haves the most efficient public transport siystem.

I believe "all in one" is supposed to still be referring to the seven days ticket. However, it almost sounds like the phrase "All in all", which means something like "overall" or "to conclude". "All in all, it's a pretty good deal!"
I've used "it's" to specify that we are still talking about this ticket, and a comma to differentiate it from the rest of the sentence.

After singular objects, "have" has to become "has".

There is an urban miyth in Latin Americ about the ga that German people are sullen, but I noticrealized that it's a lie, t. They are nice, very polite and beautiful.

"To notice" means to observe. Like, "I noticed a large crack in the window."
"To realize" is a step up from noticing. Instead of just observing, you are now using the information to make a conclusion. "I then noticed a big rock on the ground, and realized it must've been thrown at my window."

I hope sto know another placearts of this vibrant city nextin the coming days.

It was difficult to understand this sentence in English, but my Spanish is good enough to understand what you originally meant. It's the "so" in "I hope so" that confused me the most. "I hope so" is usually a phrase all on its own, often used as a response. It might come with a "too" or a "sure", but it generally likes to be left alone in the clause.
"Will Dad be back later tonight? – Well, I sure hope so." "I really hope the team wins this game! – I hope so too, man."

Keep in mind that "another" works as a contraction of "an other". In this sentence, "other" or "more" would work better. You might use "another" if there was just ONE more place in this city you wanted to get to know.

When talking about MULTIPLE days, weeks, or months that are in the future, we'd usually use "coming" or "next few". "Now that winter is here, the coming weeks should get a bit colder."

Today I was doing sightseeing uoutside of Berlin, m. My family and I went to Postsdam, it'which is a beautiful place with a lot of palaces.

However we only coughtld visit one of them.

Its called Sans Souci's Palace, it's a big house with large gardens, fountains and longer paths.

One thing that wonderimpressed me, was the public transport,; what an efficient waysystem.

If you'd still like to use "wonder" to elicit a more fantastical emotion, you could say "One thing that was wonderous to me...". "Impressed" is a more tame synonym.

In bBerlin, you can buy a seven days ticket and you wi'll be able to take the bus, tranviam, metro, urban train, ferry and the outside train to closer cities.

The contraction of "you" and "will" is "you'll" and you'll hear that much more often in every day speech ;)

all in one soWith all of that in one ticket, this city haves the most efficient public transport siystem.

I added quite a bit here to hopefully communicate what you meant more naturally, but there are many ways to say it.

There is an urban miyth in Latin America about how the gGerman people are sullen, but I noticed that it's a lie, t. They are nice, very polite and beautiful.

I hope sto know ansee other placearts of this vibrant city in the next days.

Today I was doing sightseeing uootside of Berlin, my family and I went to Postsdam, it's a beautiful place with a lot of palaces.

However we only coughtcould only visit one of them.

Its called Sans Souci's Palace, it's a big house with large gardens, fountains and longer paths.

One thing that I wondered meabout, was the public transport, what an efficient waysetup.

In bBerlin, you can buy a seven days ticket and you will be able to take buses, tranvia,ins, the metro, urban trains, ferryies and outsideintercity train to closer cities.

The ticket is all in one so this city havs one the most efficient public transport siystems.

There is an urban miyth in Latin Americ aboua that the gGerman people are sullen, but I noticed that ithat's a linot true, they are nice, very polite and beautiful.

I hope sto know anothersee more places ofin this vibrant city nextin the next few days.