Closet man, Im young, finally started growing..
One my first grow now, and its in my closet. Thats your best bit, I have a 2.5' by 3' by 8' closet and I'm getting along pretty well. You'll need lights, better if you have good lights, such as HPS for flowering and either MH or floros for vegging. For only a couple plants, probably shouldnt have to spend to much on ventilation, just open the door once in a while, have a fan blowing air around, and maybe if you can something to draw the air out, if its small anyway.
Make sure it can be completely dark for flowering, no light can shine through at all.

but oh yeah, closet, lol... GO FOR IT, Keep posts and hope this helped..

-Travis