I was wondering if the Force helped Luke Skywalker in hitting the core of the Death Star?
It's almost certain that Luke used the Force to destroy the Death Star
If you recall the scene, he had the targeting computer aligned, but was implored by Obi-Wan to trust in the Force. So he switched off the targeting computer, and allowed himself to be guided as to when to release his torpedoes.
Also recall that there was another near miss on the port by another more experienced pilot who was using the targeting computer. The defining difference was Luke's growing affinity with the Force. So while it could have been pure, dumb luck, that's highly unlikely.
Here's the scene to remind you :)
While this answer isn't canon, it actually uses the canon entirely for its argument. It is addressed directly in this video, but the answer boils down to: yes, it was literally the only way it could have been done. (Warning: NSFW language in video)
The video points out that the missiles had to be fired under combat conditions, into a port the size of a whomp-rat, make a 90 degree turn, travel completely straight down a small corridor the length of the radius of a moon, all while reminding you that this is an exhaust port which means the heat of the entire Death Star engine was being forcefully pumped opposite to the direction of the missiles. It is scientifically completely impossible for this to happen. But it did nonetheless. How? Magic space wizards.
Oh, but all the magic space wizards are dead. Right, except for one small farm kid named Skywalker who just so happens to be the son of the legendary Annakin Skywalker who disappeared just around the time the terrifying Lord Vader with his terrifying mastery of the Force appeared. Maybe had someone told the engineer involved in the design to take magic space wizards into account in his design, he could have. The design makes it scientifically impossible for missiles to hit. If you're going to tell an engineer that magic need not be a concern, that engineer will design something as such.