if you've never grown marijuana successfully before I suggest vegging them for as long as you can, topping them somewhere a couple weeks before you change to 12/12, with stakes to support each. Skip the training/scrogging this time till you get the growing part down. the longer you veg the more you can yield. great yield an quality depend on temperature/humidity/air flow control, good watering habits and hid lights. have a blast!
plastic fencing and four posts work great. veg plants under it, weave new meristems in and out of each hole, top to even canopy, when all holes ae filled skirt under the net and flower the screen of green