new here!

First off: Darius recieved some of dem nerfs long ago, still OP if you don`t get countered.

Now: Welcome to the LoL section and to the community.

I would suggest starting with learning the basics of the game: last hitting, farming, trading with the enemy [ in damage ], sustaining, map awareness, objective play, team fights, warding, counter jungling, possitioning. Choose a couple of champions, let`s say 3 main adcs you are gonna learn to play at your best so you can get into the game and just master them for a start: learn what your champion is capeble of, when to engage in combat, learn to read your supports play since some support play deffesivly like me for example, and some are offensive. When playing adc your possitioning is very important: you should try and stay at the back and hit primary targets like the enemy adc/ap carry or who ever the team chooses to focus. There is this thing called kiting: hiting the enemy while dodging his attack and staying out of his rage [ if your enemy is melee ] . You should also learn to keep track of the dragon and baron timers, they are above the scoreboard.

Those are some basic tips that I can give you for now, since I`m too lazy to type any further, hope some of this information helps you.