Regardless of the country you live in, ‘your life is your responsibility’. First of all make sure you have a solid foundation on whatever skills you preferred. Sri Lankan who has a solid education always live very comfortably in USA same as in Sri Lanka. Not to forget, those who work really hard. They also end up living a very comfortable life.
If you can show enough funds to cover expenses throughout the trip(air fair+ accommodation+ foods+ etc...), valid reason for travelling and strong ties to Sri Lanka( proofs of return) then you can apply directly to visit visa from U.S. Embassy in Sri Lanka.