You want the wave near your turret, so Kennen cannot ult on you easily and set up ganks for his jungler. Moreover, his q poke is harder to land from that position. Try not to push the wave when you are farming with q.

3Q>E max Go Doran’s Shield and Second wind for sustain. If you struggle in the matchup, go Fleet footwork, if not Lethal tempo is fine. Play around the bushes to avoid getting auto attacked often in the early game. Avoid tanking his empowered w autos since they almost always combo into his active w. Stand behind minions to avoid his q or dodge perpendicular to Kennen if you are caught in the open. If you are both six, ult when you are going to get stunned from his passive or when he ults to avoid his ult damage. Wit’s End is recommended as a first item, but nashor’s tooth is viable.

Do not trade with Kennen pre six. He has the range and mobility to kite you and run you down. Trades after six are still not favorable until you have Wit’s End since you lack enough magic resist to run him down.