I don't LST my plants, until their height starts being an issue, during flowering ... no real advantage in possibly stressing a plant that young ... I would wait a bit ... I usually crop the growing tip, and leave it at that, but, that's just me ... your mainstem looks pretty thin, you should keep an oscillating fan on it, 24/7, to strengthen it ... right now, it likely couldn't support buds (add more soil to your pot, too, it will help support the plant) ... :smokin: