You want the wave on your side so you can freely poke her without him being able to dash onto you easily.

Try to kite back and space her. Never Q2 and E into her when her cooldowns are up. Respect her level 1 and level 6 all-in damage.

Riven wants to hard trade on you level 1 with q. Ward the bush near you when you get to lane so you can’t get cheesed. Use Q1 and use your E to track her when she uses a spell to dodge it. Be careful about Eing forward. Riven has long cooldowns in the early game so if she wastes her Q or E try to look for a heavy combo onto her with your W. Post six use your ult for the movement speed to chase or run away from her.