Luke Skywalker is one of Star Wars' most powerful Jedi, but his training didn't last as long as some fans might think. As the Star Wars franchise has grown, the path to becoming a Jedi remains a vital part of the story. The original trilogy saw Luke's ascension as a Jedi, the prequels focused on Anakin Skywalker's rise before becoming Darth Vader, and the sequel trilogy put Rey's training with the Force at the forefront.
Thanks to these protagonists, Star Wars has shown several different paths to becoming a Jedi. During the time of the Jedi Order, children began training to become a Jedi at a very young age, with Anakin viewed as being behind when he was just nine-years-old. This is quite different from the path that Luke went on during the original trilogy. Luke was 19-years-old when he learned about his connection to the Force and began to learn about it from Obi-Wan Kenobi. Luke's introduction to the Force allowed him to blow up the Death Star, but it isn't until after Star Wars: A New Hope that Luke actually began training.
Even though there are three years between A New Hope and Star Wars: The Empire Strikes Back, Luke didn't do too much training between the films. Comics have shown him doing some light combat training with droids, having a few lightsaber fights, and using Kenobi's journal to try and get a better understanding of the Force. But, Luke's formal training as a Jedi doesn't come until he meets Yoda on Dagobah. The Jedi Master begins to teach Luke about the Force, and he is shown making progress during the sessions. It isn't clear precisely how long Luke trains with Yoda, but it can't be more than a few days at the most.
After getting a crash course on the Force from Yoda in The Empire Strikes Back, Luke spends the next year training so he could be as powerful as he was in Star Wars: Return of the Jedi. The exact nature of Luke's training during this time isn't known, but the beginning of the movie makes it clear that he's learned a lot in the last year. Whether its Force chokes, mind tricks, or his improved agility, Luke's new abilities can only be the result of training. The evolution of his practice is even signified by Luke crafting his green lightsaber, which is an important event for a Jedi.
If Luke's time training as a Jedi starts with Yoda and ends with Return of the Jedi, then he only spends about a year practicing in the ways of the Force. It's actually a comparable amount of time that it takes Rey to go from training with Luke in Star Wars: The Last Jedi to her heightened power level in Star Wars: The Rise of Skywalker, which some have complained happened too quickly. But, the truth is that Rey trained as a Jedi for just about as long as Luke did. Some could consider that Luke's training lasts four years, though, if what he does on his own between A New Hope and Empire Strikes Back is included. Either way, this isn't a long time for Luke to go from having no knowledge of his abilities with the Force to one of the most powerful Jedi ever seen in Star Wars.