Time for a haircut??

when is too young to defoliate? Is it beneficial in minimizing space and pushing bud growth? Can i cut big i cut to lowest leaves on this plant even without having a strong side branch?

Not sure there is anything blocking anything. I would leave it personally.

second thought can we get more details. Is this under a light or outside?

First can we not use the term defoliate? It scares me when gardeners say that. You can prune now. And you probably should prune now before the plant grows much more if what you want is a more dense growth habit. When you prune, and you probably know this but I'ma tell you anyhow, prune just above the node you want to activate. And don't be afraid of pruning hard. Cannabis can take it. Hope that helps.

Not really much there to defoliate. Leave it alone and get it under a light. Can't see you getting much of a window grow but good luck