Kylo Ren is really Ben Solo, son of Han Solo and Princess (now General) Leia. Han is killed by Ren in Starkiller Base. Tapping into her dormant Force powers, Rey fights Ren in the snow outside, as the planet is ripped apart after the strike team scores a fatal blow. Separated by a chasm, she and Finn escape on the Millennium Falcon while Kylo Ren, injured, is retrieved and taken to Supreme Leader Snoke to complete his training.
Back with the Resistance, R2-D2 awakes from his low power mode and provides the missing piece of the map leading to the location of Luke Skywalker. Rey takes his lightsaber and flies out on the Falcon with Chewbacca, meeting Luke, who's standing along on a cliff, clearly having sensed her pending arrival...
Jon Sandys ★
Answer: Any answer would be conjecture - best just watch the next movie.