How Lee Harvey Oswald managed to kill JFK

I have been reading stuff about how Lee Harvey Oswald killed JFK and I find this assassination to have been quite mysterious. I don’t have experience with guns, but come to think of it; how did Lee Harvey Oswald, a man who was acting alone manage to take three shots with a faulty gun and make two accurate hits? Consider that JFK’s car was moving away from the assassin, the car was at one point blocked from the view of the assassin by an oak tree, and that a team of riffle experts drawn from the FBI and the army couldn’t accurately simulate the shooting accuracy and speed combination that was portrayed by Lee Harvey Oswald? I have tried to seek answers online but all that I find are conspiracy theories. Anyone with a better explanation?