IMO first you need to ask yourself can I tend 24 plants? And have you over done that kind of growing? Because; let me share with you. It is a pain in the ass.
You will spend a lot of time in your room messing with your plants. I hope you know what you are in for. But if you are going to do it, here is the answer to your question.
First you need to determine how many sq ft you have in the room. Then, do the calculation to determine how many lumens per sq ft your light is emiting.
That answers the first part. Next, get two air cooled hoods and a inline fan and suck cold air from outside your room drag it across your sealed lights and release it outside the room again. "that will help keep temps down.
You will need to keep the room in the 70's with the lights on and fans running, I promise it is harder than you think it is. Try a ventless room air conditioner. Make sure to get a temp and humitity gauge "7.00"at Wally World.
Get some good beans or clones and have at it. There are a million things I could tell you, but it is trial and error.
Good Luck with your grow. If you want more info from me. PM me.
Post pics when you get it going.