Serious spoilers. Highlight if you want to know.
Kylo Ren (Adam Driver) is Han and Leia's son. Obsessed with his grandfather (Anakin Skywalker/Darth Vader) and the Sith. Wants to be one. He is Rey's brother and Luke Skywalker's nephew.
Rey is Han and Leia's daughter. She is Kylo's sister and Luke Skywalker's niece. She is good.
The black guy is Finn. He is a stormtrooper who wants to defect from the Empire. By the way, since it has been thirty years Star Wars time (32 years real time: 1983-2015), the Empire, fractured and badly damaged from Return of the Jedi, is now called The First Order.