Note: This a Guide for non expierienced Riven players.

Riven is not that strong at lvl 1. Thats why i recommend to skill your E first to avoid taking free damage from any Poke lanes. If you manage to harras your enemie with basic attacks you should be able to perform an all in at lvl 3 with ignite. After 6 make sure to use your Ghostblade while ulting for max dmg output with ult. Always chain your Q combo with W to make sure the last Q lands on your enemie. Use your E to avoid dmg like barrier or to gapclose. Only
perform your windslash when your enemie is stunned by W.

You can always engage fights with ult/ghostblade combo. Just make sure your team will follow up