She's actually extremely simple to play, just looks complicated. You're better off maxing Q first in most situation and just focus on landing E and then you can just press WWQ to spawn 2 plants and that combo will take 1/3 to half hp off almost every other AP in the game. You're pretty much guaranteed to kill anyone from half health if you have ignite and/or Ult available. She might get more complicated to play if her numbers ever get nerfed, but as it is they are way too high so there's very variation that you actually have to do in order to win lane.