About the Rules in the USA

[Luis]

Hey pals, I'm a Chinese in-campus college student. And got certificate here under FIBA rules. I was wondering about the rules in the USA, do USA has some different rules in different associations or league? For example, between NCAA & some senior highs. I might fly USA for school later and wanna officiate some games there. Who could offer me some free sites of downloading the rule books, thank you!
By the way, are the non-USA people permitted to get some ref certificate in the States.