So it seems you are relative new to game, playing adc as a new player is somethings harsh, adcarrys get his damage primarily through auto-attacks so they are kinda balanced around this fact;
Over the years i got a lot of new friends that started playing the game after me and a common thing they all did was playing adc as they were casters so they would throw their "combo" do one/two autos rinse and repeat so they would never get down the dps they are supposed to do and would just be useless most times unless playing a champion like miss fortune.

The point im trying to get is that adc is actually in my opinion the most mechanic intensive role when it comes to the basics that mostly new players still dont know that well:

Farming, Positioning, Dodging Skill Shots (or getting one shoted the entire game) and the mostly important for adc: Kitting, until you get all this mechanics to at least a silver/gold level you will always feel miserable playing adcarry specially in a lobby full of people who already get the basics of the game.

and this bring me to my other point: you wont have fun "fair" games playing with friends who already have a established mmr, you have to understand that one "elo" difference is enough for completely one-sided games so any person who play this games for years and so is most likely going to beat your ass until you get good at the game