need some help and mashwara!

making things short, have a mamu living in united states whos been in contact with me since 6 years, he has spent 30 years of his life on the streets of new york. he really wants me to be with him there as he has childs of his own. we are not a big wealthy family, but the point is also he has never done anything like this to get or to sponsor someone there. for me i have done grads recently and looking to get admitted for masters. how can i do this to get there legally? there is no chance for me to get a visit visa since i never had a business or something. can someone experienced tell me the path or any mashwara how can i be able to travel to them legally, easily? jazakallah