On this page, you can learn Japanese with a Japanese song. The title of the song is Thank you which is ありがとう in Japanese sung by Yu Takahashi.
The lyric for you to learn is from 1:15 up to 1:26 in the video.
If you want to say ‘thank you very much’, add ございます at the end of ありがとう.
(You were born to this world)
この means ‘this’. 世界（せ・かい）means ‘world’.
君（きみ）means ‘you’. In this case, it is somebody important such as your child or loved one. 人（ひと）means ‘person’. A という B is equal to ‘B called A’.
が is a topic marking particle and does not mean anything.
生まれて（う・まれて）means ‘born’. きて is てform of ‘come’ so 生まれてきて means ‘come (to this world) to be born’.
くれた is put after てform when you want to be more thankful. こと at the end of the sentence is same as こと used for Noun Infinitive.
If you say この世界に君が生まれたこと, it still means the same as この世界に君という人が生まれてきてくれたこと. You can say that the person is very important by adding という人 and きてくれた.