who I am. (Not technically incorrect, but we would say "Who am I" or "About me")

Hi, my name is Carlos, I have am 40 years old., I am a Brazilian guy born in São Paulo. I am married and have two little kids, the eldest is 3 years old and the youngest is 1 year old.(1) I enjoy meeting experiencing different new(2) cultures and meeting new people and I´m now with working on a project to communicate in their native language.(3) I like to listen to music I like listening to music (4), I am now through in a phase of "piano guys" and "2Cellos",. I also like to read, I love John Grisham novels, although lately I have been focusing focused on technical reading. What I most like to do most do in my free time is to play with my kids, whether taking them to swimming, or cycling or at to the playground. (You play with your kids AT the playground, but take them TO the playground)
Often as I can I like to go to the beach as often as I can although my actual current (5) city (Campinas) is about 3 hours from the sea ...
I also like to play sports, especially playing tennis and walking.
Movies are another passion, but I'd rather watch at home rather than go to the movies.

1 No need to repeat in the same sentence

2 'New' is not incorrect but 'different' emphasises the point better

3 This sentence is correct but a bit messy. You could try something like "I am studying in order to communicate in their native language"

4 You were correct, but it reads better using the active tense 

5 This is a mistake English speakers make in Portuguese as well. Atual=current 

Well done, it was still easy to read and you are able to get your point across very well. The mistakes you made were only small and you will begin to recognise them the more you read and listen to the language.