you will never ever fit 20fully grown plants to 12x12 room when they are fully grown unless ya gonna grow dwarfs. id take de wardrobe out from the room and build or buy slimline cabinet against one of de walls and use that for veg.and de way ya have no experience id go for autoflovering feminised seeds.that way ya knw that yar not gonna get any males .and ya gonna get at least smthing out from them.tho thats just what i think..