18% win rate non toxic Riven main, looking for tips to stop getting reported by teammates

I'm currently playing a lot of Riven because I enjoy her, despite losing all my placements and then some. My problem is I seem to get beaten by the other top laner in cs early on and can never catch up, leading to me getting killed a bunch of times and ending up with a KDA of something like 0/4/1 after 20 mins or so. Would just love it for someone to just bring me up to par on the basics of how to play the game, and understanding when to do things. I'm used to being good at basically every game I play, but league is completely new to me and I can't stand looking like a brain dead Riven main. PLS send help, ty <3{{champion:92}}
Report as:
Offensive Spam Harassment Incorrect Board