What to do if my father passed away and my stepmom said that he left nothing for me?

In South Carolina, if there is no will, the deceased is said to have died intestate.  This means that his spouse will inherit one-half of his estate and all of his children (no matter whether by 1st, 2d or other marriage or outside of marriage) will share the other half of his estate.  Thuis you are entitled to up to one half of his estate, depending on whether or not you have siblings.  If he and his wife held assets jointly, you would still share in his one-half of those assets (except for jopint and survivor bank accounts or other assets.)

I am so sorry for your loss.  If your father died with out a Will that is called "intestate" and then the intestacy laws in the state would decide how his estate is distributed.  Here is the thing: if his assets were jointly held with your step mother then they would have passed to her automatically upon his death.  Any of his estate that was not jointly held you would get a part of.  You need to find out how assets were held.  If she files a probate proceeding it is a public record.  You can look at the file.  Good luck.