Too soon to start training?

[Canachris]

I should know this, I've done it in the past. But the brain issues I'm dealing with everything just confuses me. My girls are around 3-4 weeks, I plan on using dry nutes and scratching them to the top soil. So I need to try an keep maybe 6" of space between the lower branches. there are 4 lower branches still very small that I'd like to chop off. cheezz that was long winded, so my question is should I wait until they get a little bigger? s it better to trim before watering or after? I'll try an post pics.the 2 small are current plants the bigger is past grow

 

[Roy Growin]

I top at node 3-5, as soon as the plant is big enough to get hold of
Training starts about a week later when the shoots start to grow out
Great colour