What forms must I fill as a foreing resident?

I'm 25 years old and have lived in Chile for 20 years, I only have the US citizenship because I was physically born in US soil and lived there during my first 5 years. After that I've had zero contact with the US (even my both parents are chilean), I studied in Chile, started working last year in a chilean company and opened a bank account on a chilean bank. I pay my taxes to the chilean goverment, have a chilean health insurance and a pseudo Retirement Account in Chile (it works differently here). Doing self research, my total earnings from my work is below the max of the Foreing Earning Income Exclusion.