How to win more?

So as a new player (level 27 now, since I bought the boosts to help level up and get those capsules), how do I win more in the later game? I did play every role and figured I do better when I support my team in general and that role fits me. So, how do you stay ahead of the enemy team or comeback if we're behind? I have a 52% win-rate which is pretty bad to me, and I feel like that should be higher and better. So any tips would be appreciated :)

P.S: I also appreciate the responses from my last post, awesome community to be a part of! :)