When should I start training / trimming my plants?

Hey everybody. I’m growing 4 bluedream plants inside a 3/3 tent under 600w / 250true watt LED fixture in a soil medium. Veg is going quite well but I’m wondering when I should start training my plants? Any links to videos or tips would be greatly appreciated .

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I was planning on switching my lights from LED to a 600w HPS closer to flower. Unfortunately I wasn’t aware of the importance of truewatts when I purchased my LED.

You're good to go now if they're growing healthy and vigorously, I personally would top them and bend them gently over to expose the sides then train all the sides as they get longer