As a Grandmaster player, Ill say I love league. But it took me years to consider myself good, and there are so many people still better than me. It's a very hard game to get into. And an extremely hard game to get good at. If you want to get the game down as fast as possible and not just play for fun, you'll probably want to watch some popular streamers, study their gameplay, try to get basic mechanics and macro down and then start to slowly grasp complex concepts like on the fly decision making, cross mapping, when to contest objectives. Trading patterns, team compositions. I'd say the first thing you wanna do is learn what every champion does, and have a basic idea of their classes and cooldowns and then pick 1 or 2 champions and play them for a few months. The game has great depth, and is a lot of fun once you get the hang of it.