Legal Question in Real Estate Law in California

No, an unlicensed person who is not a principal (the buyer or seller) cannot negotiate the terms of a real-estate deal nor collect a commission. There are limited exceptions including one for lawyers who negotiate deals in the course of representing a client.

Also, "Realtor" is a trademark for a member of a private professional organization of agents and brokers who have become members and have subscribed to its privately-devised sets of standards and goals. Not all licensees are Realtors, but all Realtors are licensees in some state or other.