>>316357596
it's easy to pick up by playing on a table that keeps rules for you. Try Mahjong Soul, do tutorial and play a couple times, you'll be ready to play at a very basic level. If you want to be competent at it you'll need to memorize a few dozen possible hands, but you can start by knowing 3-5 most common ones and play by aiming for getting those. Expand the list later.
/vrg/ mahjong friends will help you with rest.