In dire need of help (with decision making, maybe mechanics, etc.)

So I've been playing League.. for about 4-5 years, but didn't really play competitively until Season 2. I went from Bronze to Gold in Season 3, but after that, I've been sitting between Gold 5 to Gold 3 (rare occasion I've made it to Gold 2 and Gold 1.) I'm currently an ADC main, and I'm ok with Mid and Support, but I feel like I'm just flopping on other lanes. I know a common suggestion would be to look at replays, so I guess my first question is what would the best replay system that's currently out (that's not op.gg, I'd much prefer if it's a program, not a site to go to.) Other than that, it'd be nice if someone could help me out with what decisions I should make after laning phase ^^ IGN: LunariarWarrior