Prop 215 says you can have 12 immature OR 6 mature plants. The prop also states that you are allowed to have up to 8 oz on hand. I also grow with 2 other people. The first month I start my clones and then put them in plastic solo cups. From there I veg for 2 months in one gallon pots. I use T-5's from clone through vegging. Then it's in to 3 gallon pots and flower for 2 months and time to harvest. I usually move 3 plants to flower every 30 days. So after the first ones flower i have a perpetual harvest every month. It's a lot easier trimming 3 plants at a time than it is 18. It also makes it easy for me to stay under the legal limit. I have a max of 6 in flower (mature plants) so I can have another 24 (immature plants) in veg or clone stage. The hard part is keeping the vegging plants small enough until there is space available in the flower area. LST, Supercropping and small pots help with this. When I get down to 6 plants left in veg I start more clones.
There's all kinds of ways to grow. I'm sure other people on here will share their methods with you, also. This is what works for me. I actually do all my flowering outside in the free sunshine and fresh air. Because the plants have been under 18/6 light as soon as I put them outside and they sense the shorter day they start to flower. The plants love it and the ole lady doesn't bitch about the house stinking. It also keeps the electric bill under control. From 3 plants, mostly Strawberry Diesel, I usually pull about a pound of dried buds. That's more than enough for 3 people.. One other thing.. I don't use any nutes that are made for marijuana !!! Lots of people do and have great success but I find a good balanced 20 10 20 fertilizer along with my alfalfa tea works great..
Good luck !!