leauge looks so good and fun but when i start playing i feel diffrent

when i start playing i play against champs ive never seen i dont fully understand the champ im playing and im playing against vetrans that have played the game for years its no fun being stopmed every game and having no idea about what i hapeing its not fun im gaining nothing out if it i try every role it dosent matter i still have no idea what most of the champs do i watch streamers for many hours and i only see certian meta champs on there i really want to play this game and enjoy it but i cant i dont know what to do with it. ive also spent hours watching guides tutorials and still i only learn 5% of the game it would take me 6 to 9 months to learn everything