My fiance and me not married yet , I'm not citizen but I have 2 citizen kids , can I do somathing after my kids or need my green card first

Your question is unclear as to who needs immigration assistance.  Your citizen children must be 21 years old before they can sponsor a parent for a green card.  It appears from your post that you do not have a gree card yet.  If your fiance is a citizen, he could sponsor you for a fiance visa or a green card after you get married.  If you are not legally present in the U.S., but will need a waiver for your unlawful presence. I suggest that you contact an experienced immigration attorney to review your situation.  Good luck!   Mark J. Curley Curley Immigration Law www.curleylawoffice.com