You should probably read the threads regarding moving, work permits, etc. You will need to be financially independent and self sufficient to live there for at least a year to get residency then apply for work permit. All jobs, rightfully, go to Belizean citizens. If you want to "do good works" you'll have to have support from home for quite some time. You're not nearly old enough for the QRP.
But keep looking...where there's a will there's a way. Good luck.