It has already been demonstrated that Force abilities and proficiencies manifest in people before any Jedi training. What does most Jedi instruction consist of? Clear your mind. Focus. Do or do not, there is no try. I am not sure what other instruction would be involved in levitating a rock.
Luke was very unfocused. He was sheltered by his aunt and uncle and was not very self reliant. Rey is none of those things. She is very focused and extremely self reliant. She is confident and believes in herself.
Luke was incredibly confident. He was naive (as is Rey) but he had no lack of confidence. Look at the way he (clumsily) facilitated Leia’s rescue, or was the only guy on Yavin 4 who didn’t flinch at the size of the DS exhaust port. Look at the status he had acquired by TESB as a strong (and respected) military leader. Look at his insistence that he could become a Jedi despite Yoda’s dressing him down during their first meeting.
The problem was twofold - he was quick to anger and impatience, and secondly learning to use the Force is/was established as being really difficult. That’s the appeal of the Force as a narrative tool. It’s like martial arts in the Karate Kid. You don’t just switch it on because you feel like it, no matter how confident or tough or naturally gifted you are. That’s the ‘lesson’ of the OT - that just being a hot pilot or good fighter does not a Jedi make. Luke learned this the hard way.
I like the idea of Rey as something of a feral Jedi, but it’s as if the writers of these films aren’t giving the whole thing much thought beyond “hey, let’s have her do cool Jedi stuff”. Yoda expressed obvious amusement at Luke’s notion that a Jedi Master would automatically be a ‘great warrior’. Now this seems redundant. If you’re confident and can wave a stick, then mastery is just around the corner.