That's right. EVERY SINGLE Force user who ever existed needed training before being competent. Even Palpatine himself but Rey gets a pass from Jye just because...
I kinda thought the Force Dyad helped explain that also.. After touching Luke's Saber she awoke the FORCE in her. Her Dyad connection with Kylo allowed her to "catch up" with his skill level. The only reason she could beat him in TFA was 1. Kylo was injured and 2. She also is a Palpatine.
Yes, in TFA Kylo had two injuries before battling Rey - on his left side from Chewie's shot and on his right arm/shoulder from his lightsaber battle with Finn. Plus he wanted her to join him, so he held back while he thought she was contemplating his offer (when she was actually opening herself up to the Force). Hence the pregnant pause in the fight while he had her backed up at the chasm.
The other factor that people seem to forget is that she was already shown to be quite adept at fighting/defending herself with her staff, a skill which transfers somewhat and likely made a lightsaber duel seem less foreign to her.