5 minutes ago, Eoen said:No, people are born being able to use it (as can be seen in clone wars, The Phantom Menace, and Rebels) Force users who don’t get early training might suppress it in childhood. Also sometimes people awaken to it.
There's also a scene at the very end of TLJ where a small child (who most certainly hasn't had any sort of training) uses the Force to pull a broom to his hand from a few feet away. Back in Legends material (which was for the longest time the undisputed gospel) we had incidences of people using the Force in various ways without any sort of formal training; awful a story as they may have been, the first book of the Jedi Academy trilogy has Luke wandering the galaxy chasing up on people who display "unusual" traits (such as extremely good luck) as potential students for his newly-founded Jedi Praxeum on Yavin 4.
All it really seems training does is inform the student that "Hey, this crazy thing you didn't think was possible? Guess what, it's possible and you can do it if you believe strongly enough!"
In that respect, Rey has a very large running head start on Luke, since as was noted earlier in the thread, she grew up hearing stories of Luke's incredible feats. Plus, going by the TLJ novelization, she got a pretty good look into Kylo's mind during that psychic interrogation scene, which clued her in that the Force could be used to do some pretty incredible stuff. So in that respect, she did have "off camera training" in how to use the Force, which combined with the fighting/survival skills she developed put her on a much better initial footing that Luke, who had a very comfortable home life and didn't learn the Force was a thing that existed until he was legally an adult.