Champions

Hello all I am a highly ranked dota 2 player who just reached lvl 30 I have been playing league of legends for 3 months now and I qualified into...you guessed bronze so, I am wanting to carry myself to gold. Anyway, I was hoping to get some advice. I have heard things like which champion do you main and in Dota 2 there are no people who really main 1 champion we try to play to counter which I assume at higher levels in LOL people play more like I do in Dota. Okay so what I was wondering was who would be the best champions to really master and play to go from bronze to gold in a short amount of time?

I play many hours a day, so time isn't really a problem. But I have hit a point at where I am matched against champions I "counter" but I simply do not have the skill that they do. I know that when playing a counter I should have an advantage but most of the time the other player just simply outplays me. Also who should I be banning, should I try to play a certain lane etc.....

If anyone one can give me advice on 3 champions for each role I would be grateful also questionable advice is better than no advice. :)

Here are the champions I "main" in each role:

Top:

Jungle:

Mid:

Support:

ADC:

Thanks!!!!!