I'm from Cambodia.  

or I'm Cambodian.

or I live in Cambodia.

I'm Khmer Nation.

or I'm Cambodian.

or My nationality is Cambodian.

or My ethnicity is Khmer.

I need it to know more languages.  

(Why do you need to? I need to know more languages for work.)

or I want to learn more languages.

or I want to learn another language.

or I want to learn English. 

or I want to speak English.

etc.

>> Always capitalize the personal pronoun "I."

>> No spaces precede punctuation in English:

Incorrect:  I'm from Cambodia .

Correct:  I'm from Cambodia.