From a fellow grower: How many plants to start with in 144 square foot room indoor grow room
Start with one, when you got a handle on that expand
Well this can go so many ways answer these questions first
What style of grow are you going to do sog, scog, spread and let go or what ever
Dose the floor have a good clean floor drain
How big of pots you going to use
What is your electrical capacity
How much room for seedlings/ clones and veg
Is dry room and trim and curing done here to
My question is really how much are they prepared to spend lighting that square footage.
They should join the forums and help us understand the situation better.
agree with @PharmerBob if this is your 1st grow, 1 plant and learn. Hope your grow comes out great. Remember, good lighting as @KeystoneCops said.
You can also speak to how things might get exponentially more complicated and expensive when you go with 100sqft instead of 12.