First notebook entry: Introducing myself

I am learning English, because I want to work in for an foreign-funded company.

I'm actually not sure how to translate "foreign-funded company." I think you mean just a foreign company, although that phrase also doesn't sound natural either. Perhaps you should just stick with "multinational [corporation]."

My native language is Mandarin, and I grew up in China.

This is a minor nitpick because this sentence is technically correct. However, as an American, I very rarely hear anyone say their mother tongue is "Mandarin." Instead, most of us just say "Chinese," and only use "Mandarin" when we want to specify or differentiate from other dialects. Similarly, you don't hear people say 普通话 is their native language.

I am fond of listening to pop music. I usually do some reading during my leisure free time.

Americans don't say "leisure time." We say "free time," though some people might also do stuff "for leisure" (this is less common and sounds more formal).