Kalista adc - noob! Big time!

I start playing with Kalista after crafting 3 other champions and I start getting more and more interested about her. My problem is, though, that I'm only level 26. I usually play normal because bots are easy to understand and trick into winning, but players are not. My strategy with Kalista is to only farm in the early game and later buy items and make damage, attack speed and so on. And after what I've understood from internet and some friends, an ADC need a support. Well, everytime I play with Kalista, my support doesn't really supports and sometimes only stays in the turret. I once played with a team that understood I am still begginer and helped me out a lot in the game. In the late game, with my strategy I have more damag etc, but god help me if I do one kill (I get blamed of ks, and believe me, I try the hardest not to do ks 'cause I don't like it) when I make a kill is mine. So my question is if you (you, the badass adc and/or kalista players) can give some advices on how to play better, especially with Kalista, and also advices for masteries, runes, in game strategy, items, and all I need to know about being an ADC. Thank you a lot and good luck in your future games!