I started playing ranked at level 20 or even less, as soon as I had 2 accs at lvl 5. Oh, I reached diamond with 65% winrate on this first acc.
Any new players are likely to be from other mobas, and would want ranked asap. If I could not play ranked for so long, I would never have stuck with this game. Any one with proper moba experience would be able to beat the bronze / silver teams in hots.