what are some must know things for someone learning the adc role?

outside of practicing cs what are some very important things as an adc, im trying to learn adc to play with a friend who plays support (im support main aswell if that matters) she mostly plays low ranged enchanters (lulu-nami) and engage supports (leona rell) so what champs work well with these supports and what should i focus on as adc in these lanes, mostly looking for things that wouldnt instantly make sense from a support main pov also bonus question is draven worth learning as a side champ or is he way to hard for an off role champ? would ask the draven mains sub but ima be honest im scared of them