Sounds like you got lots to learn. The plant would do better in a small space (your closet) rather then sitting in a corner in your room which is what it sounds like you're doing, If you can control the heat in there, I'd definitely set it up to grow.
Lighting for vegetative growth should be 18/6, 20/4 or you can even do 24/0 (on/off), when you want to flower her you just switch the lights to 12/12 and keep it there till the end. They usually stretch 2-3 times their height prior to flowering.
I stop spraying my plants when they're past the seedling stage. And your friend is right about wanting to get oxygen to the roots, you want to have good drainage in your soil and letting it dry out is the easiest way I've found to water. You just water them when the pots feel weightless, they are much heavier when they first get watered. If you plan on using nutrients you should always start at a low dose to see how it affects your ladies and work up from there.
Most strains usually take at least 8 weeks to finish flowering