I assume you are growing bag seed. This will be a learning experience for you at best. Keep in
mind using bag seed or better yet mexican dirt weed, it is very difficult to grow indoors. First it is a pure sativa plant and doesn't grow well indoors under the best conditions. Then when you do harvest the tiny buds you will find you grew a half ounce of good mexican dirt weed if your lucky it is not a male if you grow a single plant.

Now for my suggestions.
If you are going to grow indoors and risk going to jail make it worth it.

You have an excellent space to settup. If you have a small budget start off with investing in good seeds, you can get 10 seeds for around $70.00 w/shipping from the internet. You will be getting seeds that produce plants that are geneticaly designed for growing indoors.

Now you have to think about lighting. CFL's will get you started. Look in the lighting subforum here for Ideas that will work best for you. If you do have funding for HID lighting (High Intensity Discharge) you have just under 6 sq. ft. of space so a 400watt HID light is perfect. There's a wide varietie of ballasts to choose from, for $100.00 to $250.00. I recommend htgsupply.com

Now prep the grow space looked like your interior walls are flat white already that is great, the only improvement you could do is use mylar to cover your closet walls with to reflect the lighting on your plants. other than mylar flat white is best.

Now for the most important part ventalation and odor control. Why is this important you ask. Most growers get busted by poor odor control (if you can smell it, so can everyone else!!!) You are going to need a ventalation system with a charcole filter, how you do this depends on location of this closet and the amount of stelf you need. I am going to need more info to give you the best ideas to accomplish this. What type of dwelling are you in? Do you own or rent? What is above your closet, attic?

I hope this helps
Happy growing