Everyone probably has a preference of how to amend their soil, but when I do soil ( Indoor, I usually use coco) I'll either compost my own soil or do a FFOF/Happy Frog mix, then finish with some teas or a form of supersoil. For just starting off, it is probably easier to just get a basic soil line from any of the leading companies ie. botanicare, house and garden, general hydroponics, advanced nutrients, etc. Get a good EC/PH meter (look into a Hanna or Bluelab), and some neem oil / azomax for bugs. Lastly, I would read into as much about soil as you can. There are many different soil approaches and they all will depend on how you want to grow.