Play it. Just don't go 100% ranked only.
Ranked will be harder competition at some point. If you start losing a lot and it's partially your fault (you're dying in Lane / your Lane opponents are getting kills elsewhere, etc...) for several games in a row, take a break go to normals and practice up a bit.
Basically, i think ranked play will help you continue to develop better and you'll regret not starting earlier if you start and do well in silver and get to high silver or gold for example. However if you start and lose a bunch and destroy your mmr to low bronze it will be pretty awful, so if you're not individually playing well you're better off practicing up in normals for a bit.
Also a word of advice - if you lose 2 or 3 games in a row on the same day, don't keep playing ranked for the day. It seems most players will just randomly get days where they lose every game they play - better to lose 2 or 3 than 8 or 9.