What you are asking here is kinda like asking "How long is a short rope?" There's just too many variables.

If you don't mind a friendly suggestion, go to Closet/Cabinet section on this forum and read about what others have done. You will find some really ingenius ideas for growing in closets - everything from lighting and ventilation to strains and growing techniques.

A little research will answer about 90% of your questions and then you will find lots of help here with the other 10%.

Good luck!

Oh, btw, congratulations on cleaning out your closet! LOL