i`m not a dirt grower but i`ll try to get you headed in the right diretion.i think for a 1st grow any cheap potting soil would do.some folks say that miracle grow is high in nitrogen and it could harm your babys,but i have seen gardens do very well with it.when you get you soil pickup some perlite
and mix it in with the soil.some use 75% to 25% 50-50 it all depends on the grower.the perlite helps with water retention.their are other additives as well,but this is a good start.
the number 1 problem with new growers in soil is over watering.to help with that always have runoff holes in the bottom of your pots(even the cups you start them in).an ez way to tell if they need watering is to pick them up,they will be lighter when they need watering.
as far as feeding it has alot to do with the strain your working with.the plant will tell you what it needs with color changes in the leaves.you shouldn`t need any feed for a while,till the plant gets a little bigger.
veinarde sorry but they can`t feed with the lights off.without light the leaves can`t produce the energy need to do so.