I'm pretty new to the game. Under level 30, and mostly just played a couple games here and there since beta messing around with friends, only started really caring 2 or 3 days ago. I didn't even know what 90% of the agents did that's how little I played.

Now that I'm getting into it though, I find that I'm improving really quick and having actually a lot of success playing a bit of Jett and mostly Reyna because of fun factor and because I'm honestly shit at every utility in the game besides flashes and Jett smokes. The thing is, my experience in other games tells me looking at her kit that Reyna is probably really shit, as usually "win more" mechanics are pretty bad, and she doesn't have much to help her do her job, only do it better after she accomplished it already, meaning it's probably only working because I'm carried by my aim and/or not properly placed in mmr.

So main question: What rank more or less does my pick start to matter and I have to think about it or change it? Or can I get away playing whatever I feel like indefinitely? How far can I get with let's say Reyna over others who seem to be way better alternatives?