How can I learn to play League of Legends and where can I get all updated information about the game?
The easiest way to begin your adventure in League of Legends is through the official website. The developers offer a section on their website called New Player Guide. This will give you a basic example of how the game should be played, and what are the elements you'll encounter during the game.
New Player Guide: http://gameinfo.na.leagueoflegends.com/en/game-info/get-started/new-player-guide/
My advice is to start a tutorial game to play it, then watch Youtube tutorials to see techniques and strategies for the game.