I would like to visit to Americahe USA because when ıI was a child , I saw the American life that ı watched filmwhen I was watching movies. I would like to visit the USA because when I was a child, I saw the American life when I was watching movies.

I would like to visit to America because when ıI was a child , I saw American life that ı watchedin films. I would like to visit to America because when I was a child , I saw American life in films.

"I saw American life that I watched in films" is just a tiny bit awkward. You can simplify to "I saw American life in films"

I would like to visit to America, because when ıI was a child , I saw how American life was in films that ıI watched films. I would like to visit America, because when I was a child, I saw how American life was in films that I watched.

That’s why ıI want to visit the United States of America. That’s why I want to visit the United States of America.

Using America is correct, but as a side note, America is a whole continent.

That’s why ıI want to visit America That’s why I want to visit America

That’'s why ıI want to visit America. That's why I want to visit America.