where do i fim or whatever

I will try to help. I don't have any pictures so i'll do my best. To fim a plant branch all you have to do is cut the growing tip through the middle. O.K. .... if you look really closely at the very end of any branch, but mainly the plant top you will see that at the end appears tiny little leaves just starting to become a brach or node. further investigation will reveal that this tip is a small ball of growth. using a sharp blade cut through the middle of that. if you go too low you will top the plant; too high and you mutilate the future growth.
looking at your pics i would not suggest this. I would top each plant. then concentrate on developing the two braches that emerge from that to fill your canopy...... everything looks super... thank you!!

 

Arent these too young to do this with? Mine turned 14 today from when they cracked the soil.. I was going to wait for more nodes of growth. They are similar size.

 

here's a pic.

 

No its not too young, you can top and or Fimm from the 3rd leaf set.

 

but are my tops too big now to fim? shall i wait till the next set?