Vanilla Kush CFL Grow First Time

[PhatJay]

My plant is about 4 weeks old, when should i consider moving to the flowering stage??

This depends on a couple of factors, like what lights you are going to use during the flowering period and what grow style you are using. Assuming that you are going to continue using CFL's and let your plant grow naturally (no LST, SCROG etc) I would say kick it into flower now. Your plant is going to double in height before it is ready for harvest and CFL's have poor light penetration.

Have you lowered your lights yet?

Do you have any 2700k bulbs for the flower period? or that 150w HPS?

Is this plant big enough to take a few clones from??

Yes

And some of the older leafs are showing some brown spots...maybe nute burn?? any thoughts??

Nute burn shows on the very tips of the leaves starting at the bottom and working up. That isn't nute burn. Lower leaves that are not getting much light tend to die off, it could be that or may be an indicator of a slight nutritional problem. Don't panic... just keep an eye on it. If the new leaves look good then old leaves are generally old news