Haw can I join with my family who live in the USA?

My sister lives and works in New York (Brooklyn) where she has two children and is divorced from her husband. She lives alone and wants to join with my family in Albania . She keeps my surname Hida . She thinks that she can take all us in USA . But if the American Law does not prevent any legal way to join these two families , I wish to find out a way that my boys can become Americans. I am over 55 years old, and I have two children older than 18 years old . I live with my wife and both children . Thay have no problems with Albanian law and thay have finished the Military Service . I and my wife are good workers . My childrens knows English and are good workers too . If my sister find out a job for my two boys can they work and live in USA ? If the only person who must join with my sister which has 10 years in America will be me , can my children go there and I stay in Albania ? I want the best for my childrens . I want that they built theyr life there because I belive in Right of American Law and I am not able to work anymore there.