Your support staff receive O-2 visa to accompany you. Your spouse and unmarried children under 21 get O-3 . P- 2 is for artist or entertainer who comes to perform under a reciprocal arrangement. P- 3 is for people who are coaching, performing, or teaching a program which is culturally unique . You need a job offer from an US Employer, first.
All categories require evidence of accomplishment .
You need a job offer from them in US O and P visa holders do not need to show intent to return from US when applying. Applying for a green card while in US will not jeopardize your status .Having one of these visa is no legal advantage, though in applying for green card. You can look for an employer while you are there who can sponsor you for green card . Check out other categories . There is no annual quota for O, P, R visas.